drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 /*
  83  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  84  * Then when using 32 bit integers x * m may overflow during the calculation.
  85  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  86  * calculates the same, but prevents the overflow when both m and d
  87  * are "small" numbers (like HZ and USER_HZ).
  88  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  89  * in 32 bits.
  90  */
  91 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  92
  93 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  94
  95 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  96 /* N.B. This variable is readable and writeable via
  97    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  98    of this size (or less if there is not enough memory) will be reserved
  99    for use by this file descriptor. [Deprecated usage: this variable is also
 100    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
 101    the kernel (i.e. it is not a module).] */
 102 static int def_reserved_size = -1;      /* picks up init parameter */
 103 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 104
 105 static int scatter_elem_sz = SG_SCATTER_SZ;
 106 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 107
 108 #define SG_SECTOR_SZ 512
 109
 110 static int sg_add_device(struct device *, struct class_interface *);
 111 static void sg_remove_device(struct device *, struct class_interface *);
 112
 113 static DEFINE_IDR(sg_index_idr);
 114 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 115                                                            file descriptor list for device */
 116
 117 static struct class_interface sg_interface = {
 118         .add_dev        = sg_add_device,
 119         .remove_dev     = sg_remove_device,
 120 };
 121
 122 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 123         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 124         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 125         unsigned bufflen;       /* Size of (aggregate) data buffer */
 126         struct page **pages;
 127         int page_order;
 128         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 129         unsigned char cmd_opcode; /* first byte of command */
 130 } Sg_scatter_hold;
 131
 132 struct sg_device;               /* forward declarations */
 133 struct sg_fd;
 134
 135 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 136         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 137         struct sg_fd *parentfp; /* NULL -> not in use */
 138         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 139         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 140         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 141         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 142         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 143         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 144         /* done protected by rq_list_lock */
 145         char done;              /* 0->before bh, 1->before read, 2->read */
 146         struct request *rq;
 147         struct bio *bio;
 148         struct execute_work ew;
 149 } Sg_request;
 150
 151 typedef struct sg_fd {          /* holds the state of a file descriptor */
 152         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 153         struct sg_device *parentdp;     /* owning device */
 154         wait_queue_head_t read_wait;    /* queue read until command done */
 155         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 156         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 157         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 158         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 159         unsigned save_scat_len; /* original length of trunc. scat. element */
 160         Sg_request *headrp;     /* head of request slist, NULL->empty */
 161         struct fasync_struct *async_qp; /* used by asynchronous notification */
 162         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 163         char low_dma;           /* as in parent but possibly overridden to 1 */
 164         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 165         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 166         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 167         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 168         char mmap_called;       /* 0 -> mmap() never called on this fd */
 169         struct kref f_ref;
 170         struct execute_work ew;
 171 } Sg_fd;
 172
 173 typedef struct sg_device { /* holds the state of each scsi generic device */
 174         struct scsi_device *device;
 175         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 176         struct mutex open_rel_lock;     /* held when in open() or release() */
 177         int sg_tablesize;       /* adapter's max scatter-gather table size */
 178         u32 index;              /* device index number */
 179         struct list_head sfds;
 180         rwlock_t sfd_lock;      /* protect access to sfd list */
 181         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 182         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 183         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 184         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 185         struct gendisk *disk;
 186         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 187         struct kref d_ref;
 188 } Sg_device;
 189
 190 /* tasklet or soft irq callback */
 191 static void sg_rq_end_io(struct request *rq, int uptodate);
 192 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 193 static int sg_finish_rem_req(Sg_request * srp);
 194 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 195 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 196                            Sg_request * srp);
 197 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 198                         const char __user *buf, size_t count, int blocking,
 199                         int read_only, int sg_io_owned, Sg_request **o_srp);
 200 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 201                            unsigned char *cmnd, int timeout, int blocking);
 202 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 203 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 204 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 205 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 206 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 207 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 208 static void sg_remove_sfp(struct kref *);
 209 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 210 static Sg_request *sg_add_request(Sg_fd * sfp);
 211 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 212 static int sg_res_in_use(Sg_fd * sfp);
 213 static Sg_device *sg_get_dev(int dev);
 214 static void sg_device_destroy(struct kref *kref);
 215
 216 #define SZ_SG_HEADER sizeof(struct sg_header)
 217 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 218 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 219 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 220
 221 #define sg_printk(prefix, sdp, fmt, a...) \
 222         sdev_prefix_printk(prefix, (sdp)->device,               \
 223                            (sdp)->disk->disk_name, fmt, ##a)
 224
 225 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 226 {
 227         struct sg_fd *sfp = filp->private_data;
 228
 229         if (sfp->parentdp->device->type == TYPE_SCANNER)
 230                 return 0;
 231
 232         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 233 }
 234
 235 static int
 236 open_wait(Sg_device *sdp, int flags)
 237 {
 238         int retval = 0;
 239
 240         if (flags & O_EXCL) {
 241                 while (sdp->open_cnt > 0) {
 242                         mutex_unlock(&sdp->open_rel_lock);
 243                         retval = wait_event_interruptible(sdp->open_wait,
 244                                         (atomic_read(&sdp->detaching) ||
 245                                          !sdp->open_cnt));
 246                         mutex_lock(&sdp->open_rel_lock);
 247
 248                         if (retval) /* -ERESTARTSYS */
 249                                 return retval;
 250                         if (atomic_read(&sdp->detaching))
 251                                 return -ENODEV;
 252                 }
 253         } else {
 254                 while (sdp->exclude) {
 255                         mutex_unlock(&sdp->open_rel_lock);
 256                         retval = wait_event_interruptible(sdp->open_wait,
 257                                         (atomic_read(&sdp->detaching) ||
 258                                          !sdp->exclude));
 259                         mutex_lock(&sdp->open_rel_lock);
 260
 261                         if (retval) /* -ERESTARTSYS */
 262                                 return retval;
 263                         if (atomic_read(&sdp->detaching))
 264                                 return -ENODEV;
 265                 }
 266         }
 267
 268         return retval;
 269 }
 270
 271 /* Returns 0 on success, else a negated errno value */
 272 static int
 273 sg_open(struct inode *inode, struct file *filp)
 274 {
 275         int dev = iminor(inode);
 276         int flags = filp->f_flags;
 277         struct request_queue *q;
 278         Sg_device *sdp;
 279         Sg_fd *sfp;
 280         int retval;
 281
 282         nonseekable_open(inode, filp);
 283         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 284                 return -EPERM; /* Can't lock it with read only access */
 285         sdp = sg_get_dev(dev);
 286         if (IS_ERR(sdp))
 287                 return PTR_ERR(sdp);
 288
 289         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 290                                       "sg_open: flags=0x%x\n", flags));
 291
 292         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 293         /* Prevent the device driver from vanishing while we sleep */
 294         retval = scsi_device_get(sdp->device);
 295         if (retval)
 296                 goto sg_put;
 297
 298         retval = scsi_autopm_get_device(sdp->device);
 299         if (retval)
 300                 goto sdp_put;
 301
 302         /* scsi_block_when_processing_errors() may block so bypass
 303          * check if O_NONBLOCK. Permits SCSI commands to be issued
 304          * during error recovery. Tread carefully. */
 305         if (!((flags & O_NONBLOCK) ||
 306               scsi_block_when_processing_errors(sdp->device))) {
 307                 retval = -ENXIO;
 308                 /* we are in error recovery for this device */
 309                 goto error_out;
 310         }
 311
 312         mutex_lock(&sdp->open_rel_lock);
 313         if (flags & O_NONBLOCK) {
 314                 if (flags & O_EXCL) {
 315                         if (sdp->open_cnt > 0) {
 316                                 retval = -EBUSY;
 317                                 goto error_mutex_locked;
 318                         }
 319                 } else {
 320                         if (sdp->exclude) {
 321                                 retval = -EBUSY;
 322                                 goto error_mutex_locked;
 323                         }
 324                 }
 325         } else {
 326                 retval = open_wait(sdp, flags);
 327                 if (retval) /* -ERESTARTSYS or -ENODEV */
 328                         goto error_mutex_locked;
 329         }
 330
 331         /* N.B. at this point we are holding the open_rel_lock */
 332         if (flags & O_EXCL)
 333                 sdp->exclude = true;
 334
 335         if (sdp->open_cnt < 1) {  /* no existing opens */
 336                 sdp->sgdebug = 0;
 337                 q = sdp->device->request_queue;
 338                 sdp->sg_tablesize = queue_max_segments(q);
 339         }
 340         sfp = sg_add_sfp(sdp);
 341         if (IS_ERR(sfp)) {
 342                 retval = PTR_ERR(sfp);
 343                 goto out_undo;
 344         }
 345
 346         filp->private_data = sfp;
 347         sdp->open_cnt++;
 348         mutex_unlock(&sdp->open_rel_lock);
 349
 350         retval = 0;
 351 sg_put:
 352         kref_put(&sdp->d_ref, sg_device_destroy);
 353         return retval;
 354
 355 out_undo:
 356         if (flags & O_EXCL) {
 357                 sdp->exclude = false;   /* undo if error */
 358                 wake_up_interruptible(&sdp->open_wait);
 359         }
 360 error_mutex_locked:
 361         mutex_unlock(&sdp->open_rel_lock);
 362 error_out:
 363         scsi_autopm_put_device(sdp->device);
 364 sdp_put:
 365         scsi_device_put(sdp->device);
 366         goto sg_put;
 367 }
 368
 369 /* Release resources associated with a successful sg_open()
 370  * Returns 0 on success, else a negated errno value */
 371 static int
 372 sg_release(struct inode *inode, struct file *filp)
 373 {
 374         Sg_device *sdp;
 375         Sg_fd *sfp;
 376
 377         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 378                 return -ENXIO;
 379         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 380
 381         mutex_lock(&sdp->open_rel_lock);
 382         scsi_autopm_put_device(sdp->device);
 383         kref_put(&sfp->f_ref, sg_remove_sfp);
 384         sdp->open_cnt--;
 385
 386         /* possibly many open()s waiting on exlude clearing, start many;
 387          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 388         if (sdp->exclude) {
 389                 sdp->exclude = false;
 390                 wake_up_interruptible_all(&sdp->open_wait);
 391         } else if (0 == sdp->open_cnt) {
 392                 wake_up_interruptible(&sdp->open_wait);
 393         }
 394         mutex_unlock(&sdp->open_rel_lock);
 395         return 0;
 396 }
 397
 398 static ssize_t
 399 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 400 {
 401         Sg_device *sdp;
 402         Sg_fd *sfp;
 403         Sg_request *srp;
 404         int req_pack_id = -1;
 405         sg_io_hdr_t *hp;
 406         struct sg_header *old_hdr = NULL;
 407         int retval = 0;
 408
 409         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 410                 return -ENXIO;
 411         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 412                                       "sg_read: count=%d\n", (int) count));
 413
 414         if (!access_ok(VERIFY_WRITE, buf, count))
 415                 return -EFAULT;
 416         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 417                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 418                 if (!old_hdr)
 419                         return -ENOMEM;
 420                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 421                         retval = -EFAULT;
 422                         goto free_old_hdr;
 423                 }
 424                 if (old_hdr->reply_len < 0) {
 425                         if (count >= SZ_SG_IO_HDR) {
 426                                 sg_io_hdr_t *new_hdr;
 427                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 428                                 if (!new_hdr) {
 429                                         retval = -ENOMEM;
 430                                         goto free_old_hdr;
 431                                 }
 432                                 retval =__copy_from_user
 433                                     (new_hdr, buf, SZ_SG_IO_HDR);
 434                                 req_pack_id = new_hdr->pack_id;
 435                                 kfree(new_hdr);
 436                                 if (retval) {
 437                                         retval = -EFAULT;
 438                                         goto free_old_hdr;
 439                                 }
 440                         }
 441                 } else
 442                         req_pack_id = old_hdr->pack_id;
 443         }
 444         srp = sg_get_rq_mark(sfp, req_pack_id);
 445         if (!srp) {             /* now wait on packet to arrive */
 446                 if (atomic_read(&sdp->detaching)) {
 447                         retval = -ENODEV;
 448                         goto free_old_hdr;
 449                 }
 450                 if (filp->f_flags & O_NONBLOCK) {
 451                         retval = -EAGAIN;
 452                         goto free_old_hdr;
 453                 }
 454                 retval = wait_event_interruptible(sfp->read_wait,
 455                         (atomic_read(&sdp->detaching) ||
 456                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 457                 if (atomic_read(&sdp->detaching)) {
 458                         retval = -ENODEV;
 459                         goto free_old_hdr;
 460                 }
 461                 if (retval) {
 462                         /* -ERESTARTSYS as signal hit process */
 463                         goto free_old_hdr;
 464                 }
 465         }
 466         if (srp->header.interface_id != '\0') {
 467                 retval = sg_new_read(sfp, buf, count, srp);
 468                 goto free_old_hdr;
 469         }
 470
 471         hp = &srp->header;
 472         if (old_hdr == NULL) {
 473                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 474                 if (! old_hdr) {
 475                         retval = -ENOMEM;
 476                         goto free_old_hdr;
 477                 }
 478         }
 479         memset(old_hdr, 0, SZ_SG_HEADER);
 480         old_hdr->reply_len = (int) hp->timeout;
 481         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 482         old_hdr->pack_id = hp->pack_id;
 483         old_hdr->twelve_byte =
 484             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 485         old_hdr->target_status = hp->masked_status;
 486         old_hdr->host_status = hp->host_status;
 487         old_hdr->driver_status = hp->driver_status;
 488         if ((CHECK_CONDITION & hp->masked_status) ||
 489             (DRIVER_SENSE & hp->driver_status))
 490                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 491                        sizeof (old_hdr->sense_buffer));
 492         switch (hp->host_status) {
 493         /* This setup of 'result' is for backward compatibility and is best
 494            ignored by the user who should use target, host + driver status */
 495         case DID_OK:
 496         case DID_PASSTHROUGH:
 497         case DID_SOFT_ERROR:
 498                 old_hdr->result = 0;
 499                 break;
 500         case DID_NO_CONNECT:
 501         case DID_BUS_BUSY:
 502         case DID_TIME_OUT:
 503                 old_hdr->result = EBUSY;
 504                 break;
 505         case DID_BAD_TARGET:
 506         case DID_ABORT:
 507         case DID_PARITY:
 508         case DID_RESET:
 509         case DID_BAD_INTR:
 510                 old_hdr->result = EIO;
 511                 break;
 512         case DID_ERROR:
 513                 old_hdr->result = (srp->sense_b[0] == 0 &&
 514                                   hp->masked_status == GOOD) ? 0 : EIO;
 515                 break;
 516         default:
 517                 old_hdr->result = EIO;
 518                 break;
 519         }
 520
 521         /* Now copy the result back to the user buffer.  */
 522         if (count >= SZ_SG_HEADER) {
 523                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 524                         retval = -EFAULT;
 525                         goto free_old_hdr;
 526                 }
 527                 buf += SZ_SG_HEADER;
 528                 if (count > old_hdr->reply_len)
 529                         count = old_hdr->reply_len;
 530                 if (count > SZ_SG_HEADER) {
 531                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 532                                 retval = -EFAULT;
 533                                 goto free_old_hdr;
 534                         }
 535                 }
 536         } else
 537                 count = (old_hdr->result == 0) ? 0 : -EIO;
 538         sg_finish_rem_req(srp);
 539         retval = count;
 540 free_old_hdr:
 541         kfree(old_hdr);
 542         return retval;
 543 }
 544
 545 static ssize_t
 546 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 547 {
 548         sg_io_hdr_t *hp = &srp->header;
 549         int err = 0, err2;
 550         int len;
 551
 552         if (count < SZ_SG_IO_HDR) {
 553                 err = -EINVAL;
 554                 goto err_out;
 555         }
 556         hp->sb_len_wr = 0;
 557         if ((hp->mx_sb_len > 0) && hp->sbp) {
 558                 if ((CHECK_CONDITION & hp->masked_status) ||
 559                     (DRIVER_SENSE & hp->driver_status)) {
 560                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 561                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 562                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 563                         len = (len > sb_len) ? sb_len : len;
 564                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 565                                 err = -EFAULT;
 566                                 goto err_out;
 567                         }
 568                         hp->sb_len_wr = len;
 569                 }
 570         }
 571         if (hp->masked_status || hp->host_status || hp->driver_status)
 572                 hp->info |= SG_INFO_CHECK;
 573         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 574                 err = -EFAULT;
 575                 goto err_out;
 576         }
 577 err_out:
 578         err2 = sg_finish_rem_req(srp);
 579         return err ? : err2 ? : count;
 580 }
 581
 582 static ssize_t
 583 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 584 {
 585         int mxsize, cmd_size, k;
 586         int input_size, blocking;
 587         unsigned char opcode;
 588         Sg_device *sdp;
 589         Sg_fd *sfp;
 590         Sg_request *srp;
 591         struct sg_header old_hdr;
 592         sg_io_hdr_t *hp;
 593         unsigned char cmnd[SG_MAX_CDB_SIZE];
 594
 595         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 596                 return -ENXIO;
 597         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 598                                       "sg_write: count=%d\n", (int) count));
 599         if (atomic_read(&sdp->detaching))
 600                 return -ENODEV;
 601         if (!((filp->f_flags & O_NONBLOCK) ||
 602               scsi_block_when_processing_errors(sdp->device)))
 603                 return -ENXIO;
 604
 605         if (!access_ok(VERIFY_READ, buf, count))
 606                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 607         if (count < SZ_SG_HEADER)
 608                 return -EIO;
 609         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 610                 return -EFAULT;
 611         blocking = !(filp->f_flags & O_NONBLOCK);
 612         if (old_hdr.reply_len < 0)
 613                 return sg_new_write(sfp, filp, buf, count,
 614                                     blocking, 0, 0, NULL);
 615         if (count < (SZ_SG_HEADER + 6))
 616                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 617
 618         if (!(srp = sg_add_request(sfp))) {
 619                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 620                                               "sg_write: queue full\n"));
 621                 return -EDOM;
 622         }
 623         buf += SZ_SG_HEADER;
 624         __get_user(opcode, buf);
 625         if (sfp->next_cmd_len > 0) {
 626                 cmd_size = sfp->next_cmd_len;
 627                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 628         } else {
 629                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 630                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 631                         cmd_size = 12;
 632         }
 633         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 634                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 635 /* Determine buffer size.  */
 636         input_size = count - cmd_size;
 637         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 638         mxsize -= SZ_SG_HEADER;
 639         input_size -= SZ_SG_HEADER;
 640         if (input_size < 0) {
 641                 sg_remove_request(sfp, srp);
 642                 return -EIO;    /* User did not pass enough bytes for this command. */
 643         }
 644         hp = &srp->header;
 645         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 646         hp->cmd_len = (unsigned char) cmd_size;
 647         hp->iovec_count = 0;
 648         hp->mx_sb_len = 0;
 649         if (input_size > 0)
 650                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 651                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 652         else
 653                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 654         hp->dxfer_len = mxsize;
 655         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 656             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 657                 hp->dxferp = (char __user *)buf + cmd_size;
 658         else
 659                 hp->dxferp = NULL;
 660         hp->sbp = NULL;
 661         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 662         hp->flags = input_size; /* structure abuse ... */
 663         hp->pack_id = old_hdr.pack_id;
 664         hp->usr_ptr = NULL;
 665         if (__copy_from_user(cmnd, buf, cmd_size))
 666                 return -EFAULT;
 667         /*
 668          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 669          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 670          * is a non-zero input_size, so emit a warning.
 671          */
 672         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 673                 static char cmd[TASK_COMM_LEN];
 674                 if (strcmp(current->comm, cmd)) {
 675                         printk_ratelimited(KERN_WARNING
 676                                            "sg_write: data in/out %d/%d bytes "
 677                                            "for SCSI command 0x%x-- guessing "
 678                                            "data in;\n   program %s not setting "
 679                                            "count and/or reply_len properly\n",
 680                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 681                                            input_size, (unsigned int) cmnd[0],
 682                                            current->comm);
 683                         strcpy(cmd, current->comm);
 684                 }
 685         }
 686         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 687         return (k < 0) ? k : count;
 688 }
 689
 690 static ssize_t
 691 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 692                  size_t count, int blocking, int read_only, int sg_io_owned,
 693                  Sg_request **o_srp)
 694 {
 695         int k;
 696         Sg_request *srp;
 697         sg_io_hdr_t *hp;
 698         unsigned char cmnd[SG_MAX_CDB_SIZE];
 699         int timeout;
 700         unsigned long ul_timeout;
 701
 702         if (count < SZ_SG_IO_HDR)
 703                 return -EINVAL;
 704         if (!access_ok(VERIFY_READ, buf, count))
 705                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 706
 707         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 708         if (!(srp = sg_add_request(sfp))) {
 709                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 710                                               "sg_new_write: queue full\n"));
 711                 return -EDOM;
 712         }
 713         srp->sg_io_owned = sg_io_owned;
 714         hp = &srp->header;
 715         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 716                 sg_remove_request(sfp, srp);
 717                 return -EFAULT;
 718         }
 719         if (hp->interface_id != 'S') {
 720                 sg_remove_request(sfp, srp);
 721                 return -ENOSYS;
 722         }
 723         if (hp->flags & SG_FLAG_MMAP_IO) {
 724                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 725                         sg_remove_request(sfp, srp);
 726                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 727                 }
 728                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 729                         sg_remove_request(sfp, srp);
 730                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 731                 }
 732                 if (sg_res_in_use(sfp)) {
 733                         sg_remove_request(sfp, srp);
 734                         return -EBUSY;  /* reserve buffer already being used */
 735                 }
 736         }
 737         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 738         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 739         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 740                 sg_remove_request(sfp, srp);
 741                 return -EMSGSIZE;
 742         }
 743         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 744                 sg_remove_request(sfp, srp);
 745                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 746         }
 747         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 748                 sg_remove_request(sfp, srp);
 749                 return -EFAULT;
 750         }
 751         if (read_only && sg_allow_access(file, cmnd)) {
 752                 sg_remove_request(sfp, srp);
 753                 return -EPERM;
 754         }
 755         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 756         if (k < 0)
 757                 return k;
 758         if (o_srp)
 759                 *o_srp = srp;
 760         return count;
 761 }
 762
 763 static int
 764 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 765                 unsigned char *cmnd, int timeout, int blocking)
 766 {
 767         int k, at_head;
 768         Sg_device *sdp = sfp->parentdp;
 769         sg_io_hdr_t *hp = &srp->header;
 770
 771         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 772         hp->status = 0;
 773         hp->masked_status = 0;
 774         hp->msg_status = 0;
 775         hp->info = 0;
 776         hp->host_status = 0;
 777         hp->driver_status = 0;
 778         hp->resid = 0;
 779         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 780                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 781                         (int) cmnd[0], (int) hp->cmd_len));
 782
 783         k = sg_start_req(srp, cmnd);
 784         if (k) {
 785                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 786                         "sg_common_write: start_req err=%d\n", k));
 787                 sg_finish_rem_req(srp);
 788                 return k;       /* probably out of space --> ENOMEM */
 789         }
 790         if (atomic_read(&sdp->detaching)) {
 791                 if (srp->bio) {
 792                         if (srp->rq->cmd != srp->rq->__cmd)
 793                                 kfree(srp->rq->cmd);
 794
 795                         blk_end_request_all(srp->rq, -EIO);
 796                         srp->rq = NULL;
 797                 }
 798
 799                 sg_finish_rem_req(srp);
 800                 return -ENODEV;
 801         }
 802
 803         hp->duration = jiffies_to_msecs(jiffies);
 804         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 805             (SG_FLAG_Q_AT_TAIL & hp->flags))
 806                 at_head = 0;
 807         else
 808                 at_head = 1;
 809
 810         srp->rq->timeout = timeout;
 811         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 812         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 813                               srp->rq, at_head, sg_rq_end_io);
 814         return 0;
 815 }
 816
 817 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 818 {
 819         unsigned long flags;
 820         int ret;
 821
 822         read_lock_irqsave(&sfp->rq_list_lock, flags);
 823         ret = srp->done;
 824         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 825         return ret;
 826 }
 827
 828 static int max_sectors_bytes(struct request_queue *q)
 829 {
 830         unsigned int max_sectors = queue_max_sectors(q);
 831
 832         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 833
 834         return max_sectors << 9;
 835 }
 836
 837 static long
 838 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 839 {
 840         void __user *p = (void __user *)arg;
 841         int __user *ip = p;
 842         int result, val, read_only;
 843         Sg_device *sdp;
 844         Sg_fd *sfp;
 845         Sg_request *srp;
 846         unsigned long iflags;
 847
 848         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 849                 return -ENXIO;
 850
 851         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 852                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 853         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 854
 855         switch (cmd_in) {
 856         case SG_IO:
 857                 if (atomic_read(&sdp->detaching))
 858                         return -ENODEV;
 859                 if (!scsi_block_when_processing_errors(sdp->device))
 860                         return -ENXIO;
 861                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 862                         return -EFAULT;
 863                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 864                                  1, read_only, 1, &srp);
 865                 if (result < 0)
 866                         return result;
 867                 result = wait_event_interruptible(sfp->read_wait,
 868                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 869                 if (atomic_read(&sdp->detaching))
 870                         return -ENODEV;
 871                 write_lock_irq(&sfp->rq_list_lock);
 872                 if (srp->done) {
 873                         srp->done = 2;
 874                         write_unlock_irq(&sfp->rq_list_lock);
 875                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 876                         return (result < 0) ? result : 0;
 877                 }
 878                 srp->orphan = 1;
 879                 write_unlock_irq(&sfp->rq_list_lock);
 880                 return result;  /* -ERESTARTSYS because signal hit process */
 881         case SG_SET_TIMEOUT:
 882                 result = get_user(val, ip);
 883                 if (result)
 884                         return result;
 885                 if (val < 0)
 886                         return -EIO;
 887                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 888                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 889                 sfp->timeout_user = val;
 890                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 891
 892                 return 0;
 893         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 894                                 /* strange ..., for backward compatibility */
 895                 return sfp->timeout_user;
 896         case SG_SET_FORCE_LOW_DMA:
 897                 result = get_user(val, ip);
 898                 if (result)
 899                         return result;
 900                 if (val) {
 901                         sfp->low_dma = 1;
 902                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 903                                 val = (int) sfp->reserve.bufflen;
 904                                 sg_remove_scat(sfp, &sfp->reserve);
 905                                 sg_build_reserve(sfp, val);
 906                         }
 907                 } else {
 908                         if (atomic_read(&sdp->detaching))
 909                                 return -ENODEV;
 910                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 911                 }
 912                 return 0;
 913         case SG_GET_LOW_DMA:
 914                 return put_user((int) sfp->low_dma, ip);
 915         case SG_GET_SCSI_ID:
 916                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 917                         return -EFAULT;
 918                 else {
 919                         sg_scsi_id_t __user *sg_idp = p;
 920
 921                         if (atomic_read(&sdp->detaching))
 922                                 return -ENODEV;
 923                         __put_user((int) sdp->device->host->host_no,
 924                                    &sg_idp->host_no);
 925                         __put_user((int) sdp->device->channel,
 926                                    &sg_idp->channel);
 927                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 928                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 929                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 930                         __put_user((short) sdp->device->host->cmd_per_lun,
 931                                    &sg_idp->h_cmd_per_lun);
 932                         __put_user((short) sdp->device->queue_depth,
 933                                    &sg_idp->d_queue_depth);
 934                         __put_user(0, &sg_idp->unused[0]);
 935                         __put_user(0, &sg_idp->unused[1]);
 936                         return 0;
 937                 }
 938         case SG_SET_FORCE_PACK_ID:
 939                 result = get_user(val, ip);
 940                 if (result)
 941                         return result;
 942                 sfp->force_packid = val ? 1 : 0;
 943                 return 0;
 944         case SG_GET_PACK_ID:
 945                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 946                         return -EFAULT;
 947                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 948                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 949                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 950                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 951                                                        iflags);
 952                                 __put_user(srp->header.pack_id, ip);
 953                                 return 0;
 954                         }
 955                 }
 956                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 957                 __put_user(-1, ip);
 958                 return 0;
 959         case SG_GET_NUM_WAITING:
 960                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 961                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 962                         if ((1 == srp->done) && (!srp->sg_io_owned))
 963                                 ++val;
 964                 }
 965                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 966                 return put_user(val, ip);
 967         case SG_GET_SG_TABLESIZE:
 968                 return put_user(sdp->sg_tablesize, ip);
 969         case SG_SET_RESERVED_SIZE:
 970                 result = get_user(val, ip);
 971                 if (result)
 972                         return result;
 973                 if (val < 0)
 974                         return -EINVAL;
 975                 val = min_t(int, val,
 976                             max_sectors_bytes(sdp->device->request_queue));
 977                 if (val != sfp->reserve.bufflen) {
 978                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 979                                 return -EBUSY;
 980                         sg_remove_scat(sfp, &sfp->reserve);
 981                         sg_build_reserve(sfp, val);
 982                 }
 983                 return 0;
 984         case SG_GET_RESERVED_SIZE:
 985                 val = min_t(int, sfp->reserve.bufflen,
 986                             max_sectors_bytes(sdp->device->request_queue));
 987                 return put_user(val, ip);
 988         case SG_SET_COMMAND_Q:
 989                 result = get_user(val, ip);
 990                 if (result)
 991                         return result;
 992                 sfp->cmd_q = val ? 1 : 0;
 993                 return 0;
 994         case SG_GET_COMMAND_Q:
 995                 return put_user((int) sfp->cmd_q, ip);
 996         case SG_SET_KEEP_ORPHAN:
 997                 result = get_user(val, ip);
 998                 if (result)
 999                         return result;
1000                 sfp->keep_orphan = val;
1001                 return 0;
1002         case SG_GET_KEEP_ORPHAN:
1003                 return put_user((int) sfp->keep_orphan, ip);
1004         case SG_NEXT_CMD_LEN:
1005                 result = get_user(val, ip);
1006                 if (result)
1007                         return result;
1008                 sfp->next_cmd_len = (val > 0) ? val : 0;
1009                 return 0;
1010         case SG_GET_VERSION_NUM:
1011                 return put_user(sg_version_num, ip);
1012         case SG_GET_ACCESS_COUNT:
1013                 /* faked - we don't have a real access count anymore */
1014                 val = (sdp->device ? 1 : 0);
1015                 return put_user(val, ip);
1016         case SG_GET_REQUEST_TABLE:
1017                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1018                         return -EFAULT;
1019                 else {
1020                         sg_req_info_t *rinfo;
1021                         unsigned int ms;
1022
1023                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1024                                                                 GFP_KERNEL);
1025                         if (!rinfo)
1026                                 return -ENOMEM;
1027                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1028                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1029                              ++val, srp = srp ? srp->nextrp : srp) {
1030                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1031                                 if (srp) {
1032                                         rinfo[val].req_state = srp->done + 1;
1033                                         rinfo[val].problem =
1034                                             srp->header.masked_status &
1035                                             srp->header.host_status &
1036                                             srp->header.driver_status;
1037                                         if (srp->done)
1038                                                 rinfo[val].duration =
1039                                                         srp->header.duration;
1040                                         else {
1041                                                 ms = jiffies_to_msecs(jiffies);
1042                                                 rinfo[val].duration =
1043                                                     (ms > srp->header.duration) ?
1044                                                     (ms - srp->header.duration) : 0;
1045                                         }
1046                                         rinfo[val].orphan = srp->orphan;
1047                                         rinfo[val].sg_io_owned =
1048                                                         srp->sg_io_owned;
1049                                         rinfo[val].pack_id =
1050                                                         srp->header.pack_id;
1051                                         rinfo[val].usr_ptr =
1052                                                         srp->header.usr_ptr;
1053                                 }
1054                         }
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,
1093                                        (char *)arg);
1094         case BLKTRACESTART:
1095                 return blk_trace_startstop(sdp->device->request_queue, 1);
1096         case BLKTRACESTOP:
1097                 return blk_trace_startstop(sdp->device->request_queue, 0);
1098         case BLKTRACETEARDOWN:
1099                 return blk_trace_remove(sdp->device->request_queue);
1100         case SCSI_IOCTL_GET_IDLUN:
1101         case SCSI_IOCTL_GET_BUS_NUMBER:
1102         case SCSI_IOCTL_PROBE_HOST:
1103         case SG_GET_TRANSFORM:
1104         case SG_SCSI_RESET:
1105                 if (atomic_read(&sdp->detaching))
1106                         return -ENODEV;
1107                 break;
1108         default:
1109                 if (read_only)
1110                         return -EPERM;  /* don't know so take safe approach */
1111                 break;
1112         }
1113
1114         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1115                         cmd_in, filp->f_flags & O_NDELAY);
1116         if (result)
1117                 return result;
1118         return scsi_ioctl(sdp->device, cmd_in, p);
1119 }
1120
1121 #ifdef CONFIG_COMPAT
1122 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1123 {
1124         Sg_device *sdp;
1125         Sg_fd *sfp;
1126         struct scsi_device *sdev;
1127
1128         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1129                 return -ENXIO;
1130
1131         sdev = sdp->device;
1132         if (sdev->host->hostt->compat_ioctl) {
1133                 int ret;
1134
1135                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1136
1137                 return ret;
1138         }
1139
1140         return -ENOIOCTLCMD;
1141 }
1142 #endif
1143
1144 static unsigned int
1145 sg_poll(struct file *filp, poll_table * wait)
1146 {
1147         unsigned int res = 0;
1148         Sg_device *sdp;
1149         Sg_fd *sfp;
1150         Sg_request *srp;
1151         int count = 0;
1152         unsigned long iflags;
1153
1154         sfp = filp->private_data;
1155         if (!sfp)
1156                 return POLLERR;
1157         sdp = sfp->parentdp;
1158         if (!sdp)
1159                 return POLLERR;
1160         poll_wait(filp, &sfp->read_wait, wait);
1161         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1162         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1163                 /* if any read waiting, flag it */
1164                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1165                         res = POLLIN | POLLRDNORM;
1166                 ++count;
1167         }
1168         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1169
1170         if (atomic_read(&sdp->detaching))
1171                 res |= POLLHUP;
1172         else if (!sfp->cmd_q) {
1173                 if (0 == count)
1174                         res |= POLLOUT | POLLWRNORM;
1175         } else if (count < SG_MAX_QUEUE)
1176                 res |= POLLOUT | POLLWRNORM;
1177         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1178                                       "sg_poll: res=0x%x\n", (int) res));
1179         return res;
1180 }
1181
1182 static int
1183 sg_fasync(int fd, struct file *filp, int mode)
1184 {
1185         Sg_device *sdp;
1186         Sg_fd *sfp;
1187
1188         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1189                 return -ENXIO;
1190         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1191                                       "sg_fasync: mode=%d\n", mode));
1192
1193         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1194 }
1195
1196 static int
1197 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1198 {
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
1244         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1245                 return -ENXIO;
1246         req_sz = vma->vm_end - vma->vm_start;
1247         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1248                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1249                                       (void *) vma->vm_start, (int) req_sz));
1250         if (vma->vm_pgoff)
1251                 return -EINVAL; /* want no offset */
1252         rsv_schp = &sfp->reserve;
1253         if (req_sz > rsv_schp->bufflen)
1254                 return -ENOMEM; /* cannot map more than reserved buffer */
1255
1256         sa = vma->vm_start;
1257         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1258         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1259                 len = vma->vm_end - sa;
1260                 len = (len < length) ? len : length;
1261                 sa += len;
1262         }
1263
1264         sfp->mmap_called = 1;
1265         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1266         vma->vm_private_data = sfp;
1267         vma->vm_ops = &sg_mmap_vm_ops;
1268         return 0;
1269 }
1270
1271 static void
1272 sg_rq_end_io_usercontext(struct work_struct *work)
1273 {
1274         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1275         struct sg_fd *sfp = srp->parentfp;
1276
1277         sg_finish_rem_req(srp);
1278         kref_put(&sfp->f_ref, sg_remove_sfp);
1279 }
1280
1281 /*
1282  * This function is a "bottom half" handler that is called by the mid
1283  * level when a command is completed (or has failed).
1284  */
1285 static void
1286 sg_rq_end_io(struct request *rq, int uptodate)
1287 {
1288         struct sg_request *srp = rq->end_io_data;
1289         Sg_device *sdp;
1290         Sg_fd *sfp;
1291         unsigned long iflags;
1292         unsigned int ms;
1293         char *sense;
1294         int result, resid, done = 1;
1295
1296         if (WARN_ON(srp->done != 0))
1297                 return;
1298
1299         sfp = srp->parentfp;
1300         if (WARN_ON(sfp == NULL))
1301                 return;
1302
1303         sdp = sfp->parentdp;
1304         if (unlikely(atomic_read(&sdp->detaching)))
1305                 pr_info("%s: device detaching\n", __func__);
1306
1307         sense = rq->sense;
1308         result = rq->errors;
1309         resid = rq->resid_len;
1310
1311         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1312                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1313                                       srp->header.pack_id, result));
1314         srp->header.resid = resid;
1315         ms = jiffies_to_msecs(jiffies);
1316         srp->header.duration = (ms > srp->header.duration) ?
1317                                 (ms - srp->header.duration) : 0;
1318         if (0 != result) {
1319                 struct scsi_sense_hdr sshdr;
1320
1321                 srp->header.status = 0xff & result;
1322                 srp->header.masked_status = status_byte(result);
1323                 srp->header.msg_status = msg_byte(result);
1324                 srp->header.host_status = host_byte(result);
1325                 srp->header.driver_status = driver_byte(result);
1326                 if ((sdp->sgdebug > 0) &&
1327                     ((CHECK_CONDITION == srp->header.masked_status) ||
1328                      (COMMAND_TERMINATED == srp->header.masked_status)))
1329                         __scsi_print_sense(sdp->device, __func__, sense,
1330                                            SCSI_SENSE_BUFFERSIZE);
1331
1332                 /* Following if statement is a patch supplied by Eric Youngdale */
1333                 if (driver_byte(result) != 0
1334                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1335                     && !scsi_sense_is_deferred(&sshdr)
1336                     && sshdr.sense_key == UNIT_ATTENTION
1337                     && sdp->device->removable) {
1338                         /* Detected possible disc change. Set the bit - this */
1339                         /* may be used if there are filesystems using this device */
1340                         sdp->device->changed = 1;
1341                 }
1342         }
1343         /* Rely on write phase to clean out srp status values, so no "else" */
1344
1345         /*
1346          * Free the request as soon as it is complete so that its resources
1347          * can be reused without waiting for userspace to read() the
1348          * result.  But keep the associated bio (if any) around until
1349          * blk_rq_unmap_user() can be called from user context.
1350          */
1351         srp->rq = NULL;
1352         if (rq->cmd != rq->__cmd)
1353                 kfree(rq->cmd);
1354         __blk_put_request(rq->q, rq);
1355
1356         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1357         if (unlikely(srp->orphan)) {
1358                 if (sfp->keep_orphan)
1359                         srp->sg_io_owned = 0;
1360                 else
1361                         done = 0;
1362         }
1363         srp->done = done;
1364         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1365
1366         if (likely(done)) {
1367                 /* Now wake up any sg_read() that is waiting for this
1368                  * packet.
1369                  */
1370                 wake_up_interruptible(&sfp->read_wait);
1371                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1372                 kref_put(&sfp->f_ref, sg_remove_sfp);
1373         } else {
1374                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1375                 schedule_work(&srp->ew.work);
1376         }
1377 }
1378
1379 static const struct file_operations sg_fops = {
1380         .owner = THIS_MODULE,
1381         .read = sg_read,
1382         .write = sg_write,
1383         .poll = sg_poll,
1384         .unlocked_ioctl = sg_ioctl,
1385 #ifdef CONFIG_COMPAT
1386         .compat_ioctl = sg_compat_ioctl,
1387 #endif
1388         .open = sg_open,
1389         .mmap = sg_mmap,
1390         .release = sg_release,
1391         .fasync = sg_fasync,
1392         .llseek = no_llseek,
1393 };
1394
1395 static struct class *sg_sysfs_class;
1396
1397 static int sg_sysfs_valid = 0;
1398
1399 static Sg_device *
1400 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1401 {
1402         struct request_queue *q = scsidp->request_queue;
1403         Sg_device *sdp;
1404         unsigned long iflags;
1405         int error;
1406         u32 k;
1407
1408         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1409         if (!sdp) {
1410                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1411                             "failure\n", __func__);
1412                 return ERR_PTR(-ENOMEM);
1413         }
1414
1415         idr_preload(GFP_KERNEL);
1416         write_lock_irqsave(&sg_index_lock, iflags);
1417
1418         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1419         if (error < 0) {
1420                 if (error == -ENOSPC) {
1421                         sdev_printk(KERN_WARNING, scsidp,
1422                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1423                                     scsidp->type, SG_MAX_DEVS - 1);
1424                         error = -ENODEV;
1425                 } else {
1426                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1427                                     "allocation Sg_device failure: %d\n",
1428                                     __func__, error);
1429                 }
1430                 goto out_unlock;
1431         }
1432         k = error;
1433
1434         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1435                                         "sg_alloc: dev=%d \n", k));
1436         sprintf(disk->disk_name, "sg%d", k);
1437         disk->first_minor = k;
1438         sdp->disk = disk;
1439         sdp->device = scsidp;
1440         mutex_init(&sdp->open_rel_lock);
1441         INIT_LIST_HEAD(&sdp->sfds);
1442         init_waitqueue_head(&sdp->open_wait);
1443         atomic_set(&sdp->detaching, 0);
1444         rwlock_init(&sdp->sfd_lock);
1445         sdp->sg_tablesize = queue_max_segments(q);
1446         sdp->index = k;
1447         kref_init(&sdp->d_ref);
1448         error = 0;
1449
1450 out_unlock:
1451         write_unlock_irqrestore(&sg_index_lock, iflags);
1452         idr_preload_end();
1453
1454         if (error) {
1455                 kfree(sdp);
1456                 return ERR_PTR(error);
1457         }
1458         return sdp;
1459 }
1460
1461 static int
1462 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1463 {
1464         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1465         struct gendisk *disk;
1466         Sg_device *sdp = NULL;
1467         struct cdev * cdev = NULL;
1468         int error;
1469         unsigned long iflags;
1470
1471         disk = alloc_disk(1);
1472         if (!disk) {
1473                 pr_warn("%s: alloc_disk failed\n", __func__);
1474                 return -ENOMEM;
1475         }
1476         disk->major = SCSI_GENERIC_MAJOR;
1477
1478         error = -ENOMEM;
1479         cdev = cdev_alloc();
1480         if (!cdev) {
1481                 pr_warn("%s: cdev_alloc failed\n", __func__);
1482                 goto out;
1483         }
1484         cdev->owner = THIS_MODULE;
1485         cdev->ops = &sg_fops;
1486
1487         sdp = sg_alloc(disk, scsidp);
1488         if (IS_ERR(sdp)) {
1489                 pr_warn("%s: sg_alloc failed\n", __func__);
1490                 error = PTR_ERR(sdp);
1491                 goto out;
1492         }
1493
1494         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1495         if (error)
1496                 goto cdev_add_err;
1497
1498         sdp->cdev = cdev;
1499         if (sg_sysfs_valid) {
1500                 struct device *sg_class_member;
1501
1502                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1503                                                 MKDEV(SCSI_GENERIC_MAJOR,
1504                                                       sdp->index),
1505                                                 sdp, "%s", disk->disk_name);
1506                 if (IS_ERR(sg_class_member)) {
1507                         pr_err("%s: device_create failed\n", __func__);
1508                         error = PTR_ERR(sg_class_member);
1509                         goto cdev_add_err;
1510                 }
1511                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1512                                           &sg_class_member->kobj, "generic");
1513                 if (error)
1514                         pr_err("%s: unable to make symlink 'generic' back "
1515                                "to sg%d\n", __func__, sdp->index);
1516         } else
1517                 pr_warn("%s: sg_sys Invalid\n", __func__);
1518
1519         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1520                     "type %d\n", sdp->index, scsidp->type);
1521
1522         dev_set_drvdata(cl_dev, sdp);
1523
1524         return 0;
1525
1526 cdev_add_err:
1527         write_lock_irqsave(&sg_index_lock, iflags);
1528         idr_remove(&sg_index_idr, sdp->index);
1529         write_unlock_irqrestore(&sg_index_lock, iflags);
1530         kfree(sdp);
1531
1532 out:
1533         put_disk(disk);
1534         if (cdev)
1535                 cdev_del(cdev);
1536         return error;
1537 }
1538
1539 static void
1540 sg_device_destroy(struct kref *kref)
1541 {
1542         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1543         unsigned long flags;
1544
1545         /* CAUTION!  Note that the device can still be found via idr_find()
1546          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1547          * any other cleanup.
1548          */
1549
1550         write_lock_irqsave(&sg_index_lock, flags);
1551         idr_remove(&sg_index_idr, sdp->index);
1552         write_unlock_irqrestore(&sg_index_lock, flags);
1553
1554         SCSI_LOG_TIMEOUT(3,
1555                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1556
1557         put_disk(sdp->disk);
1558         kfree(sdp);
1559 }
1560
1561 static void
1562 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1563 {
1564         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1565         Sg_device *sdp = dev_get_drvdata(cl_dev);
1566         unsigned long iflags;
1567         Sg_fd *sfp;
1568         int val;
1569
1570         if (!sdp)
1571                 return;
1572         /* want sdp->detaching non-zero as soon as possible */
1573         val = atomic_inc_return(&sdp->detaching);
1574         if (val > 1)
1575                 return; /* only want to do following once per device */
1576
1577         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1578                                       "%s\n", __func__));
1579
1580         read_lock_irqsave(&sdp->sfd_lock, iflags);
1581         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1582                 wake_up_interruptible_all(&sfp->read_wait);
1583                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1584         }
1585         wake_up_interruptible_all(&sdp->open_wait);
1586         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1587
1588         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1589         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1590         cdev_del(sdp->cdev);
1591         sdp->cdev = NULL;
1592
1593         kref_put(&sdp->d_ref, sg_device_destroy);
1594 }
1595
1596 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1597 module_param_named(def_reserved_size, def_reserved_size, int,
1598                    S_IRUGO | S_IWUSR);
1599 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1600
1601 MODULE_AUTHOR("Douglas Gilbert");
1602 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1603 MODULE_LICENSE("GPL");
1604 MODULE_VERSION(SG_VERSION_STR);
1605 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1606
1607 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1608                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1609 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1610 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1611
1612 static int __init
1613 init_sg(void)
1614 {
1615         int rc;
1616
1617         if (scatter_elem_sz < PAGE_SIZE) {
1618                 scatter_elem_sz = PAGE_SIZE;
1619                 scatter_elem_sz_prev = scatter_elem_sz;
1620         }
1621         if (def_reserved_size >= 0)
1622                 sg_big_buff = def_reserved_size;
1623         else
1624                 def_reserved_size = sg_big_buff;
1625
1626         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1627                                     SG_MAX_DEVS, "sg");
1628         if (rc)
1629                 return rc;
1630         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1631         if ( IS_ERR(sg_sysfs_class) ) {
1632                 rc = PTR_ERR(sg_sysfs_class);
1633                 goto err_out;
1634         }
1635         sg_sysfs_valid = 1;
1636         rc = scsi_register_interface(&sg_interface);
1637         if (0 == rc) {
1638 #ifdef CONFIG_SCSI_PROC_FS
1639                 sg_proc_init();
1640 #endif                          /* CONFIG_SCSI_PROC_FS */
1641                 return 0;
1642         }
1643         class_destroy(sg_sysfs_class);
1644 err_out:
1645         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1646         return rc;
1647 }
1648
1649 static void __exit
1650 exit_sg(void)
1651 {
1652 #ifdef CONFIG_SCSI_PROC_FS
1653         sg_proc_cleanup();
1654 #endif                          /* CONFIG_SCSI_PROC_FS */
1655         scsi_unregister_interface(&sg_interface);
1656         class_destroy(sg_sysfs_class);
1657         sg_sysfs_valid = 0;
1658         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1659                                  SG_MAX_DEVS);
1660         idr_destroy(&sg_index_idr);
1661 }
1662
1663 static int
1664 sg_start_req(Sg_request *srp, unsigned char *cmd)
1665 {
1666         int res;
1667         struct request *rq;
1668         Sg_fd *sfp = srp->parentfp;
1669         sg_io_hdr_t *hp = &srp->header;
1670         int dxfer_len = (int) hp->dxfer_len;
1671         int dxfer_dir = hp->dxfer_direction;
1672         unsigned int iov_count = hp->iovec_count;
1673         Sg_scatter_hold *req_schp = &srp->data;
1674         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1675         struct request_queue *q = sfp->parentdp->device->request_queue;
1676         struct rq_map_data *md, map_data;
1677         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1678         unsigned char *long_cmdp = NULL;
1679
1680         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1681                                       "sg_start_req: dxfer_len=%d\n",
1682                                       dxfer_len));
1683
1684         if (hp->cmd_len > BLK_MAX_CDB) {
1685                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1686                 if (!long_cmdp)
1687                         return -ENOMEM;
1688         }
1689
1690         /*
1691          * NOTE
1692          *
1693          * With scsi-mq enabled, there are a fixed number of preallocated
1694          * requests equal in number to shost->can_queue.  If all of the
1695          * preallocated requests are already in use, then using GFP_ATOMIC with
1696          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1697          * will cause blk_get_request() to sleep until an active command
1698          * completes, freeing up a request.  Neither option is ideal, but
1699          * GFP_KERNEL is the better choice to prevent userspace from getting an
1700          * unexpected EWOULDBLOCK.
1701          *
1702          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1703          * does not sleep except under memory pressure.
1704          */
1705         rq = blk_get_request(q, rw, GFP_KERNEL);
1706         if (IS_ERR(rq)) {
1707                 kfree(long_cmdp);
1708                 return PTR_ERR(rq);
1709         }
1710
1711         blk_rq_set_block_pc(rq);
1712
1713         if (hp->cmd_len > BLK_MAX_CDB)
1714                 rq->cmd = long_cmdp;
1715         memcpy(rq->cmd, cmd, hp->cmd_len);
1716         rq->cmd_len = hp->cmd_len;
1717
1718         srp->rq = rq;
1719         rq->end_io_data = srp;
1720         rq->sense = srp->sense_b;
1721         rq->retries = SG_DEFAULT_RETRIES;
1722
1723         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1724                 return 0;
1725
1726         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1727             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1728             !sfp->parentdp->device->host->unchecked_isa_dma &&
1729             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1730                 md = NULL;
1731         else
1732                 md = &map_data;
1733
1734         if (md) {
1735                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1736                         sg_link_reserve(sfp, srp, dxfer_len);
1737                 else {
1738                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1739                         if (res)
1740                                 return res;
1741                 }
1742
1743                 md->pages = req_schp->pages;
1744                 md->page_order = req_schp->page_order;
1745                 md->nr_entries = req_schp->k_use_sg;
1746                 md->offset = 0;
1747                 md->null_mapped = hp->dxferp ? 0 : 1;
1748                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1749                         md->from_user = 1;
1750                 else
1751                         md->from_user = 0;
1752         }
1753
1754         if (iov_count) {
1755                 struct iovec *iov = NULL;
1756                 struct iov_iter i;
1757
1758                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1759                 if (res < 0)
1760                         return res;
1761
1762                 iov_iter_truncate(&i, hp->dxfer_len);
1763
1764                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1765                 kfree(iov);
1766         } else
1767                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1768                                       hp->dxfer_len, GFP_ATOMIC);
1769
1770         if (!res) {
1771                 srp->bio = rq->bio;
1772
1773                 if (!md) {
1774                         req_schp->dio_in_use = 1;
1775                         hp->info |= SG_INFO_DIRECT_IO;
1776                 }
1777         }
1778         return res;
1779 }
1780
1781 static int
1782 sg_finish_rem_req(Sg_request *srp)
1783 {
1784         int ret = 0;
1785
1786         Sg_fd *sfp = srp->parentfp;
1787         Sg_scatter_hold *req_schp = &srp->data;
1788
1789         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1790                                       "sg_finish_rem_req: res_used=%d\n",
1791                                       (int) srp->res_used));
1792         if (srp->bio)
1793                 ret = blk_rq_unmap_user(srp->bio);
1794
1795         if (srp->rq) {
1796                 if (srp->rq->cmd != srp->rq->__cmd)
1797                         kfree(srp->rq->cmd);
1798                 blk_put_request(srp->rq);
1799         }
1800
1801         if (srp->res_used)
1802                 sg_unlink_reserve(sfp, srp);
1803         else
1804                 sg_remove_scat(sfp, req_schp);
1805
1806         sg_remove_request(sfp, srp);
1807
1808         return ret;
1809 }
1810
1811 static int
1812 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1813 {
1814         int sg_bufflen = tablesize * sizeof(struct page *);
1815         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1816
1817         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1818         if (!schp->pages)
1819                 return -ENOMEM;
1820         schp->sglist_len = sg_bufflen;
1821         return tablesize;       /* number of scat_gath elements allocated */
1822 }
1823
1824 static int
1825 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1826 {
1827         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1828         int sg_tablesize = sfp->parentdp->sg_tablesize;
1829         int blk_size = buff_size, order;
1830         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1831
1832         if (blk_size < 0)
1833                 return -EFAULT;
1834         if (0 == blk_size)
1835                 ++blk_size;     /* don't know why */
1836         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1837         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1838         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1839                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1840                 buff_size, blk_size));
1841
1842         /* N.B. ret_sz carried into this block ... */
1843         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1844         if (mx_sc_elems < 0)
1845                 return mx_sc_elems;     /* most likely -ENOMEM */
1846
1847         num = scatter_elem_sz;
1848         if (unlikely(num != scatter_elem_sz_prev)) {
1849                 if (num < PAGE_SIZE) {
1850                         scatter_elem_sz = PAGE_SIZE;
1851                         scatter_elem_sz_prev = PAGE_SIZE;
1852                 } else
1853                         scatter_elem_sz_prev = num;
1854         }
1855
1856         if (sfp->low_dma)
1857                 gfp_mask |= GFP_DMA;
1858
1859         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1860                 gfp_mask |= __GFP_ZERO;
1861
1862         order = get_order(num);
1863 retry:
1864         ret_sz = 1 << (PAGE_SHIFT + order);
1865
1866         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1867              k++, rem_sz -= ret_sz) {
1868
1869                 num = (rem_sz > scatter_elem_sz_prev) ?
1870                         scatter_elem_sz_prev : rem_sz;
1871
1872                 schp->pages[k] = alloc_pages(gfp_mask, order);
1873                 if (!schp->pages[k])
1874                         goto out;
1875
1876                 if (num == scatter_elem_sz_prev) {
1877                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1878                                 scatter_elem_sz = ret_sz;
1879                                 scatter_elem_sz_prev = ret_sz;
1880                         }
1881                 }
1882
1883                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1884                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1885                                  k, num, ret_sz));
1886         }               /* end of for loop */
1887
1888         schp->page_order = order;
1889         schp->k_use_sg = k;
1890         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1891                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1892                          k, rem_sz));
1893
1894         schp->bufflen = blk_size;
1895         if (rem_sz > 0) /* must have failed */
1896                 return -ENOMEM;
1897         return 0;
1898 out:
1899         for (i = 0; i < k; i++)
1900                 __free_pages(schp->pages[i], order);
1901
1902         if (--order >= 0)
1903                 goto retry;
1904
1905         return -ENOMEM;
1906 }
1907
1908 static void
1909 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1910 {
1911         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1912                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1913         if (schp->pages && schp->sglist_len > 0) {
1914                 if (!schp->dio_in_use) {
1915                         int k;
1916
1917                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1918                                 SCSI_LOG_TIMEOUT(5,
1919                                         sg_printk(KERN_INFO, sfp->parentdp,
1920                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1921                                         k, schp->pages[k]));
1922                                 __free_pages(schp->pages[k], schp->page_order);
1923                         }
1924
1925                         kfree(schp->pages);
1926                 }
1927         }
1928         memset(schp, 0, sizeof (*schp));
1929 }
1930
1931 static int
1932 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1933 {
1934         Sg_scatter_hold *schp = &srp->data;
1935         int k, num;
1936
1937         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1938                          "sg_read_oxfer: num_read_xfer=%d\n",
1939                          num_read_xfer));
1940         if ((!outp) || (num_read_xfer <= 0))
1941                 return 0;
1942
1943         num = 1 << (PAGE_SHIFT + schp->page_order);
1944         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1945                 if (num > num_read_xfer) {
1946                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1947                                            num_read_xfer))
1948                                 return -EFAULT;
1949                         break;
1950                 } else {
1951                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1952                                            num))
1953                                 return -EFAULT;
1954                         num_read_xfer -= num;
1955                         if (num_read_xfer <= 0)
1956                                 break;
1957                         outp += num;
1958                 }
1959         }
1960
1961         return 0;
1962 }
1963
1964 static void
1965 sg_build_reserve(Sg_fd * sfp, int req_size)
1966 {
1967         Sg_scatter_hold *schp = &sfp->reserve;
1968
1969         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1970                          "sg_build_reserve: req_size=%d\n", req_size));
1971         do {
1972                 if (req_size < PAGE_SIZE)
1973                         req_size = PAGE_SIZE;
1974                 if (0 == sg_build_indirect(schp, sfp, req_size))
1975                         return;
1976                 else
1977                         sg_remove_scat(sfp, schp);
1978                 req_size >>= 1; /* divide by 2 */
1979         } while (req_size > (PAGE_SIZE / 2));
1980 }
1981
1982 static void
1983 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1984 {
1985         Sg_scatter_hold *req_schp = &srp->data;
1986         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1987         int k, num, rem;
1988
1989         srp->res_used = 1;
1990         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1991                          "sg_link_reserve: size=%d\n", size));
1992         rem = size;
1993
1994         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1995         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1996                 if (rem <= num) {
1997                         req_schp->k_use_sg = k + 1;
1998                         req_schp->sglist_len = rsv_schp->sglist_len;
1999                         req_schp->pages = rsv_schp->pages;
2000
2001                         req_schp->bufflen = size;
2002                         req_schp->page_order = rsv_schp->page_order;
2003                         break;
2004                 } else
2005                         rem -= num;
2006         }
2007
2008         if (k >= rsv_schp->k_use_sg)
2009                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2010                                  "sg_link_reserve: BAD size\n"));
2011 }
2012
2013 static void
2014 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2015 {
2016         Sg_scatter_hold *req_schp = &srp->data;
2017
2018         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2019                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2020                                       (int) req_schp->k_use_sg));
2021         req_schp->k_use_sg = 0;
2022         req_schp->bufflen = 0;
2023         req_schp->pages = NULL;
2024         req_schp->page_order = 0;
2025         req_schp->sglist_len = 0;
2026         sfp->save_scat_len = 0;
2027         srp->res_used = 0;
2028 }
2029
2030 static Sg_request *
2031 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2032 {
2033         Sg_request *resp;
2034         unsigned long iflags;
2035
2036         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2037         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2038                 /* look for requests that are ready + not SG_IO owned */
2039                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2040                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2041                         resp->done = 2; /* guard against other readers */
2042                         break;
2043                 }
2044         }
2045         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2046         return resp;
2047 }
2048
2049 /* always adds to end of list */
2050 static Sg_request *
2051 sg_add_request(Sg_fd * sfp)
2052 {
2053         int k;
2054         unsigned long iflags;
2055         Sg_request *resp;
2056         Sg_request *rp = sfp->req_arr;
2057
2058         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2059         resp = sfp->headrp;
2060         if (!resp) {
2061                 memset(rp, 0, sizeof (Sg_request));
2062                 rp->parentfp = sfp;
2063                 resp = rp;
2064                 sfp->headrp = resp;
2065         } else {
2066                 if (0 == sfp->cmd_q)
2067                         resp = NULL;    /* command queuing disallowed */
2068                 else {
2069                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2070                                 if (!rp->parentfp)
2071                                         break;
2072                         }
2073                         if (k < SG_MAX_QUEUE) {
2074                                 memset(rp, 0, sizeof (Sg_request));
2075                                 rp->parentfp = sfp;
2076                                 while (resp->nextrp)
2077                                         resp = resp->nextrp;
2078                                 resp->nextrp = rp;
2079                                 resp = rp;
2080                         } else
2081                                 resp = NULL;
2082                 }
2083         }
2084         if (resp) {
2085                 resp->nextrp = NULL;
2086                 resp->header.duration = jiffies_to_msecs(jiffies);
2087         }
2088         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2089         return resp;
2090 }
2091
2092 /* Return of 1 for found; 0 for not found */
2093 static int
2094 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2095 {
2096         Sg_request *prev_rp;
2097         Sg_request *rp;
2098         unsigned long iflags;
2099         int res = 0;
2100
2101         if ((!sfp) || (!srp) || (!sfp->headrp))
2102                 return res;
2103         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2104         prev_rp = sfp->headrp;
2105         if (srp == prev_rp) {
2106                 sfp->headrp = prev_rp->nextrp;
2107                 prev_rp->parentfp = NULL;
2108                 res = 1;
2109         } else {
2110                 while ((rp = prev_rp->nextrp)) {
2111                         if (srp == rp) {
2112                                 prev_rp->nextrp = rp->nextrp;
2113                                 rp->parentfp = NULL;
2114                                 res = 1;
2115                                 break;
2116                         }
2117                         prev_rp = rp;
2118                 }
2119         }
2120         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2121         return res;
2122 }
2123
2124 static Sg_fd *
2125 sg_add_sfp(Sg_device * sdp)
2126 {
2127         Sg_fd *sfp;
2128         unsigned long iflags;
2129         int bufflen;
2130
2131         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2132         if (!sfp)
2133                 return ERR_PTR(-ENOMEM);
2134
2135         init_waitqueue_head(&sfp->read_wait);
2136         rwlock_init(&sfp->rq_list_lock);
2137
2138         kref_init(&sfp->f_ref);
2139         sfp->timeout = SG_DEFAULT_TIMEOUT;
2140         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2141         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2142         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2143             sdp->device->host->unchecked_isa_dma : 1;
2144         sfp->cmd_q = SG_DEF_COMMAND_Q;
2145         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2146         sfp->parentdp = sdp;
2147         write_lock_irqsave(&sdp->sfd_lock, iflags);
2148         if (atomic_read(&sdp->detaching)) {
2149                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2150                 return ERR_PTR(-ENODEV);
2151         }
2152         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2153         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2154         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2155                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2156         if (unlikely(sg_big_buff != def_reserved_size))
2157                 sg_big_buff = def_reserved_size;
2158
2159         bufflen = min_t(int, sg_big_buff,
2160                         max_sectors_bytes(sdp->device->request_queue));
2161         sg_build_reserve(sfp, bufflen);
2162         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2163                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2164                                       sfp->reserve.bufflen,
2165                                       sfp->reserve.k_use_sg));
2166
2167         kref_get(&sdp->d_ref);
2168         __module_get(THIS_MODULE);
2169         return sfp;
2170 }
2171
2172 static void
2173 sg_remove_sfp_usercontext(struct work_struct *work)
2174 {
2175         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2176         struct sg_device *sdp = sfp->parentdp;
2177
2178         /* Cleanup any responses which were never read(). */
2179         while (sfp->headrp)
2180                 sg_finish_rem_req(sfp->headrp);
2181
2182         if (sfp->reserve.bufflen > 0) {
2183                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2184                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2185                                 (int) sfp->reserve.bufflen,
2186                                 (int) sfp->reserve.k_use_sg));
2187                 sg_remove_scat(sfp, &sfp->reserve);
2188         }
2189
2190         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2191                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2192         kfree(sfp);
2193
2194         scsi_device_put(sdp->device);
2195         kref_put(&sdp->d_ref, sg_device_destroy);
2196         module_put(THIS_MODULE);
2197 }
2198
2199 static void
2200 sg_remove_sfp(struct kref *kref)
2201 {
2202         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2203         struct sg_device *sdp = sfp->parentdp;
2204         unsigned long iflags;
2205
2206         write_lock_irqsave(&sdp->sfd_lock, iflags);
2207         list_del(&sfp->sfd_siblings);
2208         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2209
2210         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2211         schedule_work(&sfp->ew.work);
2212 }
2213
2214 static int
2215 sg_res_in_use(Sg_fd * sfp)
2216 {
2217         const Sg_request *srp;
2218         unsigned long iflags;
2219
2220         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2221         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2222                 if (srp->res_used)
2223                         break;
2224         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2225         return srp ? 1 : 0;
2226 }
2227
2228 #ifdef CONFIG_SCSI_PROC_FS
2229 static int
2230 sg_idr_max_id(int id, void *p, void *data)
2231 {
2232         int *k = data;
2233
2234         if (*k < id)
2235                 *k = id;
2236
2237         return 0;
2238 }
2239
2240 static int
2241 sg_last_dev(void)
2242 {
2243         int k = -1;
2244         unsigned long iflags;
2245
2246         read_lock_irqsave(&sg_index_lock, iflags);
2247         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2248         read_unlock_irqrestore(&sg_index_lock, iflags);
2249         return k + 1;           /* origin 1 */
2250 }
2251 #endif
2252
2253 /* must be called with sg_index_lock held */
2254 static Sg_device *sg_lookup_dev(int dev)
2255 {
2256         return idr_find(&sg_index_idr, dev);
2257 }
2258
2259 static Sg_device *
2260 sg_get_dev(int dev)
2261 {
2262         struct sg_device *sdp;
2263         unsigned long flags;
2264
2265         read_lock_irqsave(&sg_index_lock, flags);
2266         sdp = sg_lookup_dev(dev);
2267         if (!sdp)
2268                 sdp = ERR_PTR(-ENXIO);
2269         else if (atomic_read(&sdp->detaching)) {
2270                 /* If sdp->detaching, then the refcount may already be 0, in
2271                  * which case it would be a bug to do kref_get().
2272                  */
2273                 sdp = ERR_PTR(-ENODEV);
2274         } else
2275                 kref_get(&sdp->d_ref);
2276         read_unlock_irqrestore(&sg_index_lock, flags);
2277
2278         return sdp;
2279 }
2280
2281 #ifdef CONFIG_SCSI_PROC_FS
2282
2283 static struct proc_dir_entry *sg_proc_sgp = NULL;
2284
2285 static char sg_proc_sg_dirname[] = "scsi/sg";
2286
2287 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2288
2289 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2290 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2291                                   size_t count, loff_t *off);
2292 static const struct file_operations adio_fops = {
2293         .owner = THIS_MODULE,
2294         .open = sg_proc_single_open_adio,
2295         .read = seq_read,
2296         .llseek = seq_lseek,
2297         .write = sg_proc_write_adio,
2298         .release = single_release,
2299 };
2300
2301 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2302 static ssize_t sg_proc_write_dressz(struct file *filp,
2303                 const char __user *buffer, size_t count, loff_t *off);
2304 static const struct file_operations dressz_fops = {
2305         .owner = THIS_MODULE,
2306         .open = sg_proc_single_open_dressz,
2307         .read = seq_read,
2308         .llseek = seq_lseek,
2309         .write = sg_proc_write_dressz,
2310         .release = single_release,
2311 };
2312
2313 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2314 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2315 static const struct file_operations version_fops = {
2316         .owner = THIS_MODULE,
2317         .open = sg_proc_single_open_version,
2318         .read = seq_read,
2319         .llseek = seq_lseek,
2320         .release = single_release,
2321 };
2322
2323 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2324 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2325 static const struct file_operations devhdr_fops = {
2326         .owner = THIS_MODULE,
2327         .open = sg_proc_single_open_devhdr,
2328         .read = seq_read,
2329         .llseek = seq_lseek,
2330         .release = single_release,
2331 };
2332
2333 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2334 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2335 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2336 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2337 static void dev_seq_stop(struct seq_file *s, void *v);
2338 static const struct file_operations dev_fops = {
2339         .owner = THIS_MODULE,
2340         .open = sg_proc_open_dev,
2341         .read = seq_read,
2342         .llseek = seq_lseek,
2343         .release = seq_release,
2344 };
2345 static const struct seq_operations dev_seq_ops = {
2346         .start = dev_seq_start,
2347         .next  = dev_seq_next,
2348         .stop  = dev_seq_stop,
2349         .show  = sg_proc_seq_show_dev,
2350 };
2351
2352 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2353 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2354 static const struct file_operations devstrs_fops = {
2355         .owner = THIS_MODULE,
2356         .open = sg_proc_open_devstrs,
2357         .read = seq_read,
2358         .llseek = seq_lseek,
2359         .release = seq_release,
2360 };
2361 static const struct seq_operations devstrs_seq_ops = {
2362         .start = dev_seq_start,
2363         .next  = dev_seq_next,
2364         .stop  = dev_seq_stop,
2365         .show  = sg_proc_seq_show_devstrs,
2366 };
2367
2368 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2369 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2370 static const struct file_operations debug_fops = {
2371         .owner = THIS_MODULE,
2372         .open = sg_proc_open_debug,
2373         .read = seq_read,
2374         .llseek = seq_lseek,
2375         .release = seq_release,
2376 };
2377 static const struct seq_operations debug_seq_ops = {
2378         .start = dev_seq_start,
2379         .next  = dev_seq_next,
2380         .stop  = dev_seq_stop,
2381         .show  = sg_proc_seq_show_debug,
2382 };
2383
2384
2385 struct sg_proc_leaf {
2386         const char * name;
2387         const struct file_operations * fops;
2388 };
2389
2390 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2391         {"allow_dio", &adio_fops},
2392         {"debug", &debug_fops},
2393         {"def_reserved_size", &dressz_fops},
2394         {"device_hdr", &devhdr_fops},
2395         {"devices", &dev_fops},
2396         {"device_strs", &devstrs_fops},
2397         {"version", &version_fops}
2398 };
2399
2400 static int
2401 sg_proc_init(void)
2402 {
2403         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2404         int k;
2405
2406         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2407         if (!sg_proc_sgp)
2408                 return 1;
2409         for (k = 0; k < num_leaves; ++k) {
2410                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2411                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2412                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2413         }
2414         return 0;
2415 }
2416
2417 static void
2418 sg_proc_cleanup(void)
2419 {
2420         int k;
2421         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2422
2423         if (!sg_proc_sgp)
2424                 return;
2425         for (k = 0; k < num_leaves; ++k)
2426                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2427         remove_proc_entry(sg_proc_sg_dirname, NULL);
2428 }
2429
2430
2431 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2432 {
2433         seq_printf(s, "%d\n", *((int *)s->private));
2434         return 0;
2435 }
2436
2437 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2438 {
2439         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2440 }
2441
2442 static ssize_t
2443 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2444                    size_t count, loff_t *off)
2445 {
2446         int err;
2447         unsigned long num;
2448
2449         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2450                 return -EACCES;
2451         err = kstrtoul_from_user(buffer, count, 0, &num);
2452         if (err)
2453                 return err;
2454         sg_allow_dio = num ? 1 : 0;
2455         return count;
2456 }
2457
2458 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2459 {
2460         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2461 }
2462
2463 static ssize_t
2464 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2465                      size_t count, loff_t *off)
2466 {
2467         int err;
2468         unsigned long k = ULONG_MAX;
2469
2470         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2471                 return -EACCES;
2472
2473         err = kstrtoul_from_user(buffer, count, 0, &k);
2474         if (err)
2475                 return err;
2476         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2477                 sg_big_buff = k;
2478                 return count;
2479         }
2480         return -ERANGE;
2481 }
2482
2483 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2484 {
2485         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2486                    sg_version_date);
2487         return 0;
2488 }
2489
2490 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2491 {
2492         return single_open(file, sg_proc_seq_show_version, NULL);
2493 }
2494
2495 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2496 {
2497         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2498         return 0;
2499 }
2500
2501 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2502 {
2503         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2504 }
2505
2506 struct sg_proc_deviter {
2507         loff_t  index;
2508         size_t  max;
2509 };
2510
2511 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2512 {
2513         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2514
2515         s->private = it;
2516         if (! it)
2517                 return NULL;
2518
2519         it->index = *pos;
2520         it->max = sg_last_dev();
2521         if (it->index >= it->max)
2522                 return NULL;
2523         return it;
2524 }
2525
2526 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2527 {
2528         struct sg_proc_deviter * it = s->private;
2529
2530         *pos = ++it->index;
2531         return (it->index < it->max) ? it : NULL;
2532 }
2533
2534 static void dev_seq_stop(struct seq_file *s, void *v)
2535 {
2536         kfree(s->private);
2537 }
2538
2539 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2540 {
2541         return seq_open(file, &dev_seq_ops);
2542 }
2543
2544 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2545 {
2546         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2547         Sg_device *sdp;
2548         struct scsi_device *scsidp;
2549         unsigned long iflags;
2550
2551         read_lock_irqsave(&sg_index_lock, iflags);
2552         sdp = it ? sg_lookup_dev(it->index) : NULL;
2553         if ((NULL == sdp) || (NULL == sdp->device) ||
2554             (atomic_read(&sdp->detaching)))
2555                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2556         else {
2557                 scsidp = sdp->device;
2558                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2559                               scsidp->host->host_no, scsidp->channel,
2560                               scsidp->id, scsidp->lun, (int) scsidp->type,
2561                               1,
2562                               (int) scsidp->queue_depth,
2563                               (int) atomic_read(&scsidp->device_busy),
2564                               (int) scsi_device_online(scsidp));
2565         }
2566         read_unlock_irqrestore(&sg_index_lock, iflags);
2567         return 0;
2568 }
2569
2570 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2571 {
2572         return seq_open(file, &devstrs_seq_ops);
2573 }
2574
2575 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2576 {
2577         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2578         Sg_device *sdp;
2579         struct scsi_device *scsidp;
2580         unsigned long iflags;
2581
2582         read_lock_irqsave(&sg_index_lock, iflags);
2583         sdp = it ? sg_lookup_dev(it->index) : NULL;
2584         scsidp = sdp ? sdp->device : NULL;
2585         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2586                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2587                            scsidp->vendor, scsidp->model, scsidp->rev);
2588         else
2589                 seq_puts(s, "<no active device>\n");
2590         read_unlock_irqrestore(&sg_index_lock, iflags);
2591         return 0;
2592 }
2593
2594 /* must be called while holding sg_index_lock */
2595 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2596 {
2597         int k, m, new_interface, blen, usg;
2598         Sg_request *srp;
2599         Sg_fd *fp;
2600         const sg_io_hdr_t *hp;
2601         const char * cp;
2602         unsigned int ms;
2603
2604         k = 0;
2605         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2606                 k++;
2607                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2608                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2609                            "(res)sgat=%d low_dma=%d\n", k,
2610                            jiffies_to_msecs(fp->timeout),
2611                            fp->reserve.bufflen,
2612                            (int) fp->reserve.k_use_sg,
2613                            (int) fp->low_dma);
2614                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2615                            (int) fp->cmd_q, (int) fp->force_packid,
2616                            (int) fp->keep_orphan);
2617                 for (m = 0, srp = fp->headrp;
2618                                 srp != NULL;
2619                                 ++m, srp = srp->nextrp) {
2620                         hp = &srp->header;
2621                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2622                         if (srp->res_used) {
2623                                 if (new_interface &&
2624                                     (SG_FLAG_MMAP_IO & hp->flags))
2625                                         cp = "     mmap>> ";
2626                                 else
2627                                         cp = "     rb>> ";
2628                         } else {
2629                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2630                                         cp = "     dio>> ";
2631                                 else
2632                                         cp = "     ";
2633                         }
2634                         seq_puts(s, cp);
2635                         blen = srp->data.bufflen;
2636                         usg = srp->data.k_use_sg;
2637                         seq_puts(s, srp->done ?
2638                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2639                                   : "act:");
2640                         seq_printf(s, " id=%d blen=%d",
2641                                    srp->header.pack_id, blen);
2642                         if (srp->done)
2643                                 seq_printf(s, " dur=%d", hp->duration);
2644                         else {
2645                                 ms = jiffies_to_msecs(jiffies);
2646                                 seq_printf(s, " t_o/elap=%d/%d",
2647                                         (new_interface ? hp->timeout :
2648                                                   jiffies_to_msecs(fp->timeout)),
2649                                         (ms > hp->duration ? ms - hp->duration : 0));
2650                         }
2651                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2652                                    (int) srp->data.cmd_opcode);
2653                 }
2654                 if (0 == m)
2655                         seq_puts(s, "     No requests active\n");
2656                 read_unlock(&fp->rq_list_lock);
2657         }
2658 }
2659
2660 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2661 {
2662         return seq_open(file, &debug_seq_ops);
2663 }
2664
2665 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2666 {
2667         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2668         Sg_device *sdp;
2669         unsigned long iflags;
2670
2671         if (it && (0 == it->index))
2672                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2673                            (int)it->max, sg_big_buff);
2674
2675         read_lock_irqsave(&sg_index_lock, iflags);
2676         sdp = it ? sg_lookup_dev(it->index) : NULL;
2677         if (NULL == sdp)
2678                 goto skip;
2679         read_lock(&sdp->sfd_lock);
2680         if (!list_empty(&sdp->sfds)) {
2681                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2682                 if (atomic_read(&sdp->detaching))
2683                         seq_puts(s, "detaching pending close ");
2684                 else if (sdp->device) {
2685                         struct scsi_device *scsidp = sdp->device;
2686
2687                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2688                                    scsidp->host->host_no,
2689                                    scsidp->channel, scsidp->id,
2690                                    scsidp->lun,
2691                                    scsidp->host->hostt->emulated);
2692                 }
2693                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2694                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2695                 sg_proc_debug_helper(s, sdp);
2696         }
2697         read_unlock(&sdp->sfd_lock);
2698 skip:
2699         read_unlock_irqrestore(&sg_index_lock, iflags);
2700         return 0;
2701 }
2702
2703 #endif                          /* CONFIG_SCSI_PROC_FS */
2704
2705 module_init(init_sg);
2706 module_exit(exit_sg);