kernel/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 (unlikely(segment_eq(get_fs(), KERNEL_DS)))
 596                 return -EINVAL;
 597
 598         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 599                 return -ENXIO;
 600         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 601                                       "sg_write: count=%d\n", (int) count));
 602         if (atomic_read(&sdp->detaching))
 603                 return -ENODEV;
 604         if (!((filp->f_flags & O_NONBLOCK) ||
 605               scsi_block_when_processing_errors(sdp->device)))
 606                 return -ENXIO;
 607
 608         if (!access_ok(VERIFY_READ, buf, count))
 609                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 610         if (count < SZ_SG_HEADER)
 611                 return -EIO;
 612         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 613                 return -EFAULT;
 614         blocking = !(filp->f_flags & O_NONBLOCK);
 615         if (old_hdr.reply_len < 0)
 616                 return sg_new_write(sfp, filp, buf, count,
 617                                     blocking, 0, 0, NULL);
 618         if (count < (SZ_SG_HEADER + 6))
 619                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 620
 621         if (!(srp = sg_add_request(sfp))) {
 622                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 623                                               "sg_write: queue full\n"));
 624                 return -EDOM;
 625         }
 626         buf += SZ_SG_HEADER;
 627         __get_user(opcode, buf);
 628         if (sfp->next_cmd_len > 0) {
 629                 cmd_size = sfp->next_cmd_len;
 630                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 631         } else {
 632                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 633                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 634                         cmd_size = 12;
 635         }
 636         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 637                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 638 /* Determine buffer size.  */
 639         input_size = count - cmd_size;
 640         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 641         mxsize -= SZ_SG_HEADER;
 642         input_size -= SZ_SG_HEADER;
 643         if (input_size < 0) {
 644                 sg_remove_request(sfp, srp);
 645                 return -EIO;    /* User did not pass enough bytes for this command. */
 646         }
 647         hp = &srp->header;
 648         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 649         hp->cmd_len = (unsigned char) cmd_size;
 650         hp->iovec_count = 0;
 651         hp->mx_sb_len = 0;
 652         if (input_size > 0)
 653                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 654                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 655         else
 656                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 657         hp->dxfer_len = mxsize;
 658         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 659             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 660                 hp->dxferp = (char __user *)buf + cmd_size;
 661         else
 662                 hp->dxferp = NULL;
 663         hp->sbp = NULL;
 664         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 665         hp->flags = input_size; /* structure abuse ... */
 666         hp->pack_id = old_hdr.pack_id;
 667         hp->usr_ptr = NULL;
 668         if (__copy_from_user(cmnd, buf, cmd_size))
 669                 return -EFAULT;
 670         /*
 671          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 672          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 673          * is a non-zero input_size, so emit a warning.
 674          */
 675         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 676                 static char cmd[TASK_COMM_LEN];
 677                 if (strcmp(current->comm, cmd)) {
 678                         printk_ratelimited(KERN_WARNING
 679                                            "sg_write: data in/out %d/%d bytes "
 680                                            "for SCSI command 0x%x-- guessing "
 681                                            "data in;\n   program %s not setting "
 682                                            "count and/or reply_len properly\n",
 683                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 684                                            input_size, (unsigned int) cmnd[0],
 685                                            current->comm);
 686                         strcpy(cmd, current->comm);
 687                 }
 688         }
 689         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 690         return (k < 0) ? k : count;
 691 }
 692
 693 static ssize_t
 694 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 695                  size_t count, int blocking, int read_only, int sg_io_owned,
 696                  Sg_request **o_srp)
 697 {
 698         int k;
 699         Sg_request *srp;
 700         sg_io_hdr_t *hp;
 701         unsigned char cmnd[SG_MAX_CDB_SIZE];
 702         int timeout;
 703         unsigned long ul_timeout;
 704
 705         if (count < SZ_SG_IO_HDR)
 706                 return -EINVAL;
 707         if (!access_ok(VERIFY_READ, buf, count))
 708                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 709
 710         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 711         if (!(srp = sg_add_request(sfp))) {
 712                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 713                                               "sg_new_write: queue full\n"));
 714                 return -EDOM;
 715         }
 716         srp->sg_io_owned = sg_io_owned;
 717         hp = &srp->header;
 718         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 719                 sg_remove_request(sfp, srp);
 720                 return -EFAULT;
 721         }
 722         if (hp->interface_id != 'S') {
 723                 sg_remove_request(sfp, srp);
 724                 return -ENOSYS;
 725         }
 726         if (hp->flags & SG_FLAG_MMAP_IO) {
 727                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 728                         sg_remove_request(sfp, srp);
 729                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 730                 }
 731                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 732                         sg_remove_request(sfp, srp);
 733                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 734                 }
 735                 if (sg_res_in_use(sfp)) {
 736                         sg_remove_request(sfp, srp);
 737                         return -EBUSY;  /* reserve buffer already being used */
 738                 }
 739         }
 740         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 741         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 742         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EMSGSIZE;
 745         }
 746         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 747                 sg_remove_request(sfp, srp);
 748                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 749         }
 750         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 751                 sg_remove_request(sfp, srp);
 752                 return -EFAULT;
 753         }
 754         if (read_only && sg_allow_access(file, cmnd)) {
 755                 sg_remove_request(sfp, srp);
 756                 return -EPERM;
 757         }
 758         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 759         if (k < 0)
 760                 return k;
 761         if (o_srp)
 762                 *o_srp = srp;
 763         return count;
 764 }
 765
 766 static int
 767 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 768                 unsigned char *cmnd, int timeout, int blocking)
 769 {
 770         int k, at_head;
 771         Sg_device *sdp = sfp->parentdp;
 772         sg_io_hdr_t *hp = &srp->header;
 773
 774         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 775         hp->status = 0;
 776         hp->masked_status = 0;
 777         hp->msg_status = 0;
 778         hp->info = 0;
 779         hp->host_status = 0;
 780         hp->driver_status = 0;
 781         hp->resid = 0;
 782         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 783                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 784                         (int) cmnd[0], (int) hp->cmd_len));
 785
 786         k = sg_start_req(srp, cmnd);
 787         if (k) {
 788                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 789                         "sg_common_write: start_req err=%d\n", k));
 790                 sg_finish_rem_req(srp);
 791                 return k;       /* probably out of space --> ENOMEM */
 792         }
 793         if (atomic_read(&sdp->detaching)) {
 794                 if (srp->bio) {
 795                         if (srp->rq->cmd != srp->rq->__cmd)
 796                                 kfree(srp->rq->cmd);
 797
 798                         blk_end_request_all(srp->rq, -EIO);
 799                         srp->rq = NULL;
 800                 }
 801
 802                 sg_finish_rem_req(srp);
 803                 return -ENODEV;
 804         }
 805
 806         hp->duration = jiffies_to_msecs(jiffies);
 807         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 808             (SG_FLAG_Q_AT_TAIL & hp->flags))
 809                 at_head = 0;
 810         else
 811                 at_head = 1;
 812
 813         srp->rq->timeout = timeout;
 814         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 815         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 816                               srp->rq, at_head, sg_rq_end_io);
 817         return 0;
 818 }
 819
 820 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 821 {
 822         unsigned long flags;
 823         int ret;
 824
 825         read_lock_irqsave(&sfp->rq_list_lock, flags);
 826         ret = srp->done;
 827         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 828         return ret;
 829 }
 830
 831 static int max_sectors_bytes(struct request_queue *q)
 832 {
 833         unsigned int max_sectors = queue_max_sectors(q);
 834
 835         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 836
 837         return max_sectors << 9;
 838 }
 839
 840 static long
 841 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 842 {
 843         void __user *p = (void __user *)arg;
 844         int __user *ip = p;
 845         int result, val, read_only;
 846         Sg_device *sdp;
 847         Sg_fd *sfp;
 848         Sg_request *srp;
 849         unsigned long iflags;
 850
 851         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 852                 return -ENXIO;
 853
 854         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 855                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 856         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 857
 858         switch (cmd_in) {
 859         case SG_IO:
 860                 if (atomic_read(&sdp->detaching))
 861                         return -ENODEV;
 862                 if (!scsi_block_when_processing_errors(sdp->device))
 863                         return -ENXIO;
 864                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 865                         return -EFAULT;
 866                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 867                                  1, read_only, 1, &srp);
 868                 if (result < 0)
 869                         return result;
 870                 result = wait_event_interruptible(sfp->read_wait,
 871                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 872                 if (atomic_read(&sdp->detaching))
 873                         return -ENODEV;
 874                 write_lock_irq(&sfp->rq_list_lock);
 875                 if (srp->done) {
 876                         srp->done = 2;
 877                         write_unlock_irq(&sfp->rq_list_lock);
 878                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 879                         return (result < 0) ? result : 0;
 880                 }
 881                 srp->orphan = 1;
 882                 write_unlock_irq(&sfp->rq_list_lock);
 883                 return result;  /* -ERESTARTSYS because signal hit process */
 884         case SG_SET_TIMEOUT:
 885                 result = get_user(val, ip);
 886                 if (result)
 887                         return result;
 888                 if (val < 0)
 889                         return -EIO;
 890                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 891                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 892                 sfp->timeout_user = val;
 893                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 894
 895                 return 0;
 896         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 897                                 /* strange ..., for backward compatibility */
 898                 return sfp->timeout_user;
 899         case SG_SET_FORCE_LOW_DMA:
 900                 result = get_user(val, ip);
 901                 if (result)
 902                         return result;
 903                 if (val) {
 904                         sfp->low_dma = 1;
 905                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 906                                 val = (int) sfp->reserve.bufflen;
 907                                 sg_remove_scat(sfp, &sfp->reserve);
 908                                 sg_build_reserve(sfp, val);
 909                         }
 910                 } else {
 911                         if (atomic_read(&sdp->detaching))
 912                                 return -ENODEV;
 913                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 914                 }
 915                 return 0;
 916         case SG_GET_LOW_DMA:
 917                 return put_user((int) sfp->low_dma, ip);
 918         case SG_GET_SCSI_ID:
 919                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 920                         return -EFAULT;
 921                 else {
 922                         sg_scsi_id_t __user *sg_idp = p;
 923
 924                         if (atomic_read(&sdp->detaching))
 925                                 return -ENODEV;
 926                         __put_user((int) sdp->device->host->host_no,
 927                                    &sg_idp->host_no);
 928                         __put_user((int) sdp->device->channel,
 929                                    &sg_idp->channel);
 930                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 931                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 932                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 933                         __put_user((short) sdp->device->host->cmd_per_lun,
 934                                    &sg_idp->h_cmd_per_lun);
 935                         __put_user((short) sdp->device->queue_depth,
 936                                    &sg_idp->d_queue_depth);
 937                         __put_user(0, &sg_idp->unused[0]);
 938                         __put_user(0, &sg_idp->unused[1]);
 939                         return 0;
 940                 }
 941         case SG_SET_FORCE_PACK_ID:
 942                 result = get_user(val, ip);
 943                 if (result)
 944                         return result;
 945                 sfp->force_packid = val ? 1 : 0;
 946                 return 0;
 947         case SG_GET_PACK_ID:
 948                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 949                         return -EFAULT;
 950                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 951                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 952                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 953                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 954                                                        iflags);
 955                                 __put_user(srp->header.pack_id, ip);
 956                                 return 0;
 957                         }
 958                 }
 959                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 960                 __put_user(-1, ip);
 961                 return 0;
 962         case SG_GET_NUM_WAITING:
 963                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 964                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 965                         if ((1 == srp->done) && (!srp->sg_io_owned))
 966                                 ++val;
 967                 }
 968                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 969                 return put_user(val, ip);
 970         case SG_GET_SG_TABLESIZE:
 971                 return put_user(sdp->sg_tablesize, ip);
 972         case SG_SET_RESERVED_SIZE:
 973                 result = get_user(val, ip);
 974                 if (result)
 975                         return result;
 976                 if (val < 0)
 977                         return -EINVAL;
 978                 val = min_t(int, val,
 979                             max_sectors_bytes(sdp->device->request_queue));
 980                 if (val != sfp->reserve.bufflen) {
 981                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 982                                 return -EBUSY;
 983                         sg_remove_scat(sfp, &sfp->reserve);
 984                         sg_build_reserve(sfp, val);
 985                 }
 986                 return 0;
 987         case SG_GET_RESERVED_SIZE:
 988                 val = min_t(int, sfp->reserve.bufflen,
 989                             max_sectors_bytes(sdp->device->request_queue));
 990                 return put_user(val, ip);
 991         case SG_SET_COMMAND_Q:
 992                 result = get_user(val, ip);
 993                 if (result)
 994                         return result;
 995                 sfp->cmd_q = val ? 1 : 0;
 996                 return 0;
 997         case SG_GET_COMMAND_Q:
 998                 return put_user((int) sfp->cmd_q, ip);
 999         case SG_SET_KEEP_ORPHAN:
1000                 result = get_user(val, ip);
1001                 if (result)
1002                         return result;
1003                 sfp->keep_orphan = val;
1004                 return 0;
1005         case SG_GET_KEEP_ORPHAN:
1006                 return put_user((int) sfp->keep_orphan, ip);
1007         case SG_NEXT_CMD_LEN:
1008                 result = get_user(val, ip);
1009                 if (result)
1010                         return result;
1011                 sfp->next_cmd_len = (val > 0) ? val : 0;
1012                 return 0;
1013         case SG_GET_VERSION_NUM:
1014                 return put_user(sg_version_num, ip);
1015         case SG_GET_ACCESS_COUNT:
1016                 /* faked - we don't have a real access count anymore */
1017                 val = (sdp->device ? 1 : 0);
1018                 return put_user(val, ip);
1019         case SG_GET_REQUEST_TABLE:
1020                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1021                         return -EFAULT;
1022                 else {
1023                         sg_req_info_t *rinfo;
1024                         unsigned int ms;
1025
1026                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1027                                                                 GFP_KERNEL);
1028                         if (!rinfo)
1029                                 return -ENOMEM;
1030                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1031                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1032                              ++val, srp = srp ? srp->nextrp : srp) {
1033                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1034                                 if (srp) {
1035                                         rinfo[val].req_state = srp->done + 1;
1036                                         rinfo[val].problem =
1037                                             srp->header.masked_status &
1038                                             srp->header.host_status &
1039                                             srp->header.driver_status;
1040                                         if (srp->done)
1041                                                 rinfo[val].duration =
1042                                                         srp->header.duration;
1043                                         else {
1044                                                 ms = jiffies_to_msecs(jiffies);
1045                                                 rinfo[val].duration =
1046                                                     (ms > srp->header.duration) ?
1047                                                     (ms - srp->header.duration) : 0;
1048                                         }
1049                                         rinfo[val].orphan = srp->orphan;
1050                                         rinfo[val].sg_io_owned =
1051                                                         srp->sg_io_owned;
1052                                         rinfo[val].pack_id =
1053                                                         srp->header.pack_id;
1054                                         rinfo[val].usr_ptr =
1055                                                         srp->header.usr_ptr;
1056                                 }
1057                         }
1058                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1059                         result = __copy_to_user(p, rinfo,
1060                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1061                         result = result ? -EFAULT : 0;
1062                         kfree(rinfo);
1063                         return result;
1064                 }
1065         case SG_EMULATED_HOST:
1066                 if (atomic_read(&sdp->detaching))
1067                         return -ENODEV;
1068                 return put_user(sdp->device->host->hostt->emulated, ip);
1069         case SCSI_IOCTL_SEND_COMMAND:
1070                 if (atomic_read(&sdp->detaching))
1071                         return -ENODEV;
1072                 if (read_only) {
1073                         unsigned char opcode = WRITE_6;
1074                         Scsi_Ioctl_Command __user *siocp = p;
1075
1076                         if (copy_from_user(&opcode, siocp->data, 1))
1077                                 return -EFAULT;
1078                         if (sg_allow_access(filp, &opcode))
1079                                 return -EPERM;
1080                 }
1081                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1082         case SG_SET_DEBUG:
1083                 result = get_user(val, ip);
1084                 if (result)
1085                         return result;
1086                 sdp->sgdebug = (char) val;
1087                 return 0;
1088         case BLKSECTGET:
1089                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1090                                 ip);
1091         case BLKTRACESETUP:
1092                 return blk_trace_setup(sdp->device->request_queue,
1093                                        sdp->disk->disk_name,
1094                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1095                                        NULL,
1096                                        (char *)arg);
1097         case BLKTRACESTART:
1098                 return blk_trace_startstop(sdp->device->request_queue, 1);
1099         case BLKTRACESTOP:
1100                 return blk_trace_startstop(sdp->device->request_queue, 0);
1101         case BLKTRACETEARDOWN:
1102                 return blk_trace_remove(sdp->device->request_queue);
1103         case SCSI_IOCTL_GET_IDLUN:
1104         case SCSI_IOCTL_GET_BUS_NUMBER:
1105         case SCSI_IOCTL_PROBE_HOST:
1106         case SG_GET_TRANSFORM:
1107         case SG_SCSI_RESET:
1108                 if (atomic_read(&sdp->detaching))
1109                         return -ENODEV;
1110                 break;
1111         default:
1112                 if (read_only)
1113                         return -EPERM;  /* don't know so take safe approach */
1114                 break;
1115         }
1116
1117         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1118                         cmd_in, filp->f_flags & O_NDELAY);
1119         if (result)
1120                 return result;
1121         return scsi_ioctl(sdp->device, cmd_in, p);
1122 }
1123
1124 #ifdef CONFIG_COMPAT
1125 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1126 {
1127         Sg_device *sdp;
1128         Sg_fd *sfp;
1129         struct scsi_device *sdev;
1130
1131         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1132                 return -ENXIO;
1133
1134         sdev = sdp->device;
1135         if (sdev->host->hostt->compat_ioctl) {
1136                 int ret;
1137
1138                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1139
1140                 return ret;
1141         }
1142
1143         return -ENOIOCTLCMD;
1144 }
1145 #endif
1146
1147 static unsigned int
1148 sg_poll(struct file *filp, poll_table * wait)
1149 {
1150         unsigned int res = 0;
1151         Sg_device *sdp;
1152         Sg_fd *sfp;
1153         Sg_request *srp;
1154         int count = 0;
1155         unsigned long iflags;
1156
1157         sfp = filp->private_data;
1158         if (!sfp)
1159                 return POLLERR;
1160         sdp = sfp->parentdp;
1161         if (!sdp)
1162                 return POLLERR;
1163         poll_wait(filp, &sfp->read_wait, wait);
1164         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1165         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1166                 /* if any read waiting, flag it */
1167                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1168                         res = POLLIN | POLLRDNORM;
1169                 ++count;
1170         }
1171         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1172
1173         if (atomic_read(&sdp->detaching))
1174                 res |= POLLHUP;
1175         else if (!sfp->cmd_q) {
1176                 if (0 == count)
1177                         res |= POLLOUT | POLLWRNORM;
1178         } else if (count < SG_MAX_QUEUE)
1179                 res |= POLLOUT | POLLWRNORM;
1180         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1181                                       "sg_poll: res=0x%x\n", (int) res));
1182         return res;
1183 }
1184
1185 static int
1186 sg_fasync(int fd, struct file *filp, int mode)
1187 {
1188         Sg_device *sdp;
1189         Sg_fd *sfp;
1190
1191         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1192                 return -ENXIO;
1193         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1194                                       "sg_fasync: mode=%d\n", mode));
1195
1196         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1197 }
1198
1199 static int
1200 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1201 {
1202         Sg_fd *sfp;
1203         unsigned long offset, len, sa;
1204         Sg_scatter_hold *rsv_schp;
1205         int k, length;
1206
1207         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1208                 return VM_FAULT_SIGBUS;
1209         rsv_schp = &sfp->reserve;
1210         offset = vmf->pgoff << PAGE_SHIFT;
1211         if (offset >= rsv_schp->bufflen)
1212                 return VM_FAULT_SIGBUS;
1213         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1214                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1215                                       offset, rsv_schp->k_use_sg));
1216         sa = vma->vm_start;
1217         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1218         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1219                 len = vma->vm_end - sa;
1220                 len = (len < length) ? len : length;
1221                 if (offset < len) {
1222                         struct page *page = nth_page(rsv_schp->pages[k],
1223                                                      offset >> PAGE_SHIFT);
1224                         get_page(page); /* increment page count */
1225                         vmf->page = page;
1226                         return 0; /* success */
1227                 }
1228                 sa += len;
1229                 offset -= len;
1230         }
1231
1232         return VM_FAULT_SIGBUS;
1233 }
1234
1235 static const struct vm_operations_struct sg_mmap_vm_ops = {
1236         .fault = sg_vma_fault,
1237 };
1238
1239 static int
1240 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1241 {
1242         Sg_fd *sfp;
1243         unsigned long req_sz, len, sa;
1244         Sg_scatter_hold *rsv_schp;
1245         int k, length;
1246
1247         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1248                 return -ENXIO;
1249         req_sz = vma->vm_end - vma->vm_start;
1250         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1251                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1252                                       (void *) vma->vm_start, (int) req_sz));
1253         if (vma->vm_pgoff)
1254                 return -EINVAL; /* want no offset */
1255         rsv_schp = &sfp->reserve;
1256         if (req_sz > rsv_schp->bufflen)
1257                 return -ENOMEM; /* cannot map more than reserved buffer */
1258
1259         sa = vma->vm_start;
1260         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1261         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1262                 len = vma->vm_end - sa;
1263                 len = (len < length) ? len : length;
1264                 sa += len;
1265         }
1266
1267         sfp->mmap_called = 1;
1268         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1269         vma->vm_private_data = sfp;
1270         vma->vm_ops = &sg_mmap_vm_ops;
1271         return 0;
1272 }
1273
1274 static void
1275 sg_rq_end_io_usercontext(struct work_struct *work)
1276 {
1277         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1278         struct sg_fd *sfp = srp->parentfp;
1279
1280         sg_finish_rem_req(srp);
1281         kref_put(&sfp->f_ref, sg_remove_sfp);
1282 }
1283
1284 /*
1285  * This function is a "bottom half" handler that is called by the mid
1286  * level when a command is completed (or has failed).
1287  */
1288 static void
1289 sg_rq_end_io(struct request *rq, int uptodate)
1290 {
1291         struct sg_request *srp = rq->end_io_data;
1292         Sg_device *sdp;
1293         Sg_fd *sfp;
1294         unsigned long iflags;
1295         unsigned int ms;
1296         char *sense;
1297         int result, resid, done = 1;
1298
1299         if (WARN_ON(srp->done != 0))
1300                 return;
1301
1302         sfp = srp->parentfp;
1303         if (WARN_ON(sfp == NULL))
1304                 return;
1305
1306         sdp = sfp->parentdp;
1307         if (unlikely(atomic_read(&sdp->detaching)))
1308                 pr_info("%s: device detaching\n", __func__);
1309
1310         sense = rq->sense;
1311         result = rq->errors;
1312         resid = rq->resid_len;
1313
1314         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1315                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1316                                       srp->header.pack_id, result));
1317         srp->header.resid = resid;
1318         ms = jiffies_to_msecs(jiffies);
1319         srp->header.duration = (ms > srp->header.duration) ?
1320                                 (ms - srp->header.duration) : 0;
1321         if (0 != result) {
1322                 struct scsi_sense_hdr sshdr;
1323
1324                 srp->header.status = 0xff & result;
1325                 srp->header.masked_status = status_byte(result);
1326                 srp->header.msg_status = msg_byte(result);
1327                 srp->header.host_status = host_byte(result);
1328                 srp->header.driver_status = driver_byte(result);
1329                 if ((sdp->sgdebug > 0) &&
1330                     ((CHECK_CONDITION == srp->header.masked_status) ||
1331                      (COMMAND_TERMINATED == srp->header.masked_status)))
1332                         __scsi_print_sense(sdp->device, __func__, sense,
1333                                            SCSI_SENSE_BUFFERSIZE);
1334
1335                 /* Following if statement is a patch supplied by Eric Youngdale */
1336                 if (driver_byte(result) != 0
1337                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1338                     && !scsi_sense_is_deferred(&sshdr)
1339                     && sshdr.sense_key == UNIT_ATTENTION
1340                     && sdp->device->removable) {
1341                         /* Detected possible disc change. Set the bit - this */
1342                         /* may be used if there are filesystems using this device */
1343                         sdp->device->changed = 1;
1344                 }
1345         }
1346         /* Rely on write phase to clean out srp status values, so no "else" */
1347
1348         /*
1349          * Free the request as soon as it is complete so that its resources
1350          * can be reused without waiting for userspace to read() the
1351          * result.  But keep the associated bio (if any) around until
1352          * blk_rq_unmap_user() can be called from user context.
1353          */
1354         srp->rq = NULL;
1355         if (rq->cmd != rq->__cmd)
1356                 kfree(rq->cmd);
1357         __blk_put_request(rq->q, rq);
1358
1359         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1360         if (unlikely(srp->orphan)) {
1361                 if (sfp->keep_orphan)
1362                         srp->sg_io_owned = 0;
1363                 else
1364                         done = 0;
1365         }
1366         srp->done = done;
1367         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1368
1369         if (likely(done)) {
1370                 /* Now wake up any sg_read() that is waiting for this
1371                  * packet.
1372                  */
1373                 wake_up_interruptible(&sfp->read_wait);
1374                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1375                 kref_put(&sfp->f_ref, sg_remove_sfp);
1376         } else {
1377                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1378                 schedule_work(&srp->ew.work);
1379         }
1380 }
1381
1382 static const struct file_operations sg_fops = {
1383         .owner = THIS_MODULE,
1384         .read = sg_read,
1385         .write = sg_write,
1386         .poll = sg_poll,
1387         .unlocked_ioctl = sg_ioctl,
1388 #ifdef CONFIG_COMPAT
1389         .compat_ioctl = sg_compat_ioctl,
1390 #endif
1391         .open = sg_open,
1392         .mmap = sg_mmap,
1393         .release = sg_release,
1394         .fasync = sg_fasync,
1395         .llseek = no_llseek,
1396 };
1397
1398 static struct class *sg_sysfs_class;
1399
1400 static int sg_sysfs_valid = 0;
1401
1402 static Sg_device *
1403 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1404 {
1405         struct request_queue *q = scsidp->request_queue;
1406         Sg_device *sdp;
1407         unsigned long iflags;
1408         int error;
1409         u32 k;
1410
1411         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1412         if (!sdp) {
1413                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1414                             "failure\n", __func__);
1415                 return ERR_PTR(-ENOMEM);
1416         }
1417
1418         idr_preload(GFP_KERNEL);
1419         write_lock_irqsave(&sg_index_lock, iflags);
1420
1421         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1422         if (error < 0) {
1423                 if (error == -ENOSPC) {
1424                         sdev_printk(KERN_WARNING, scsidp,
1425                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1426                                     scsidp->type, SG_MAX_DEVS - 1);
1427                         error = -ENODEV;
1428                 } else {
1429                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1430                                     "allocation Sg_device failure: %d\n",
1431                                     __func__, error);
1432                 }
1433                 goto out_unlock;
1434         }
1435         k = error;
1436
1437         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1438                                         "sg_alloc: dev=%d \n", k));
1439         sprintf(disk->disk_name, "sg%d", k);
1440         disk->first_minor = k;
1441         sdp->disk = disk;
1442         sdp->device = scsidp;
1443         mutex_init(&sdp->open_rel_lock);
1444         INIT_LIST_HEAD(&sdp->sfds);
1445         init_waitqueue_head(&sdp->open_wait);
1446         atomic_set(&sdp->detaching, 0);
1447         rwlock_init(&sdp->sfd_lock);
1448         sdp->sg_tablesize = queue_max_segments(q);
1449         sdp->index = k;
1450         kref_init(&sdp->d_ref);
1451         error = 0;
1452
1453 out_unlock:
1454         write_unlock_irqrestore(&sg_index_lock, iflags);
1455         idr_preload_end();
1456
1457         if (error) {
1458                 kfree(sdp);
1459                 return ERR_PTR(error);
1460         }
1461         return sdp;
1462 }
1463
1464 static int
1465 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1466 {
1467         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1468         struct gendisk *disk;
1469         Sg_device *sdp = NULL;
1470         struct cdev * cdev = NULL;
1471         int error;
1472         unsigned long iflags;
1473
1474         disk = alloc_disk(1);
1475         if (!disk) {
1476                 pr_warn("%s: alloc_disk failed\n", __func__);
1477                 return -ENOMEM;
1478         }
1479         disk->major = SCSI_GENERIC_MAJOR;
1480
1481         error = -ENOMEM;
1482         cdev = cdev_alloc();
1483         if (!cdev) {
1484                 pr_warn("%s: cdev_alloc failed\n", __func__);
1485                 goto out;
1486         }
1487         cdev->owner = THIS_MODULE;
1488         cdev->ops = &sg_fops;
1489
1490         sdp = sg_alloc(disk, scsidp);
1491         if (IS_ERR(sdp)) {
1492                 pr_warn("%s: sg_alloc failed\n", __func__);
1493                 error = PTR_ERR(sdp);
1494                 goto out;
1495         }
1496
1497         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1498         if (error)
1499                 goto cdev_add_err;
1500
1501         sdp->cdev = cdev;
1502         if (sg_sysfs_valid) {
1503                 struct device *sg_class_member;
1504
1505                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1506                                                 MKDEV(SCSI_GENERIC_MAJOR,
1507                                                       sdp->index),
1508                                                 sdp, "%s", disk->disk_name);
1509                 if (IS_ERR(sg_class_member)) {
1510                         pr_err("%s: device_create failed\n", __func__);
1511                         error = PTR_ERR(sg_class_member);
1512                         goto cdev_add_err;
1513                 }
1514                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1515                                           &sg_class_member->kobj, "generic");
1516                 if (error)
1517                         pr_err("%s: unable to make symlink 'generic' back "
1518                                "to sg%d\n", __func__, sdp->index);
1519         } else
1520                 pr_warn("%s: sg_sys Invalid\n", __func__);
1521
1522         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1523                     "type %d\n", sdp->index, scsidp->type);
1524
1525         dev_set_drvdata(cl_dev, sdp);
1526
1527         return 0;
1528
1529 cdev_add_err:
1530         write_lock_irqsave(&sg_index_lock, iflags);
1531         idr_remove(&sg_index_idr, sdp->index);
1532         write_unlock_irqrestore(&sg_index_lock, iflags);
1533         kfree(sdp);
1534
1535 out:
1536         put_disk(disk);
1537         if (cdev)
1538                 cdev_del(cdev);
1539         return error;
1540 }
1541
1542 static void
1543 sg_device_destroy(struct kref *kref)
1544 {
1545         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1546         unsigned long flags;
1547
1548         /* CAUTION!  Note that the device can still be found via idr_find()
1549          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1550          * any other cleanup.
1551          */
1552
1553         write_lock_irqsave(&sg_index_lock, flags);
1554         idr_remove(&sg_index_idr, sdp->index);
1555         write_unlock_irqrestore(&sg_index_lock, flags);
1556
1557         SCSI_LOG_TIMEOUT(3,
1558                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1559
1560         put_disk(sdp->disk);
1561         kfree(sdp);
1562 }
1563
1564 static void
1565 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1566 {
1567         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1568         Sg_device *sdp = dev_get_drvdata(cl_dev);
1569         unsigned long iflags;
1570         Sg_fd *sfp;
1571         int val;
1572
1573         if (!sdp)
1574                 return;
1575         /* want sdp->detaching non-zero as soon as possible */
1576         val = atomic_inc_return(&sdp->detaching);
1577         if (val > 1)
1578                 return; /* only want to do following once per device */
1579
1580         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1581                                       "%s\n", __func__));
1582
1583         read_lock_irqsave(&sdp->sfd_lock, iflags);
1584         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1585                 wake_up_interruptible_all(&sfp->read_wait);
1586                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1587         }
1588         wake_up_interruptible_all(&sdp->open_wait);
1589         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1590
1591         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1592         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1593         cdev_del(sdp->cdev);
1594         sdp->cdev = NULL;
1595
1596         kref_put(&sdp->d_ref, sg_device_destroy);
1597 }
1598
1599 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1600 module_param_named(def_reserved_size, def_reserved_size, int,
1601                    S_IRUGO | S_IWUSR);
1602 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1603
1604 MODULE_AUTHOR("Douglas Gilbert");
1605 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1606 MODULE_LICENSE("GPL");
1607 MODULE_VERSION(SG_VERSION_STR);
1608 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1609
1610 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1611                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1612 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1613 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1614
1615 static int __init
1616 init_sg(void)
1617 {
1618         int rc;
1619
1620         if (scatter_elem_sz < PAGE_SIZE) {
1621                 scatter_elem_sz = PAGE_SIZE;
1622                 scatter_elem_sz_prev = scatter_elem_sz;
1623         }
1624         if (def_reserved_size >= 0)
1625                 sg_big_buff = def_reserved_size;
1626         else
1627                 def_reserved_size = sg_big_buff;
1628
1629         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1630                                     SG_MAX_DEVS, "sg");
1631         if (rc)
1632                 return rc;
1633         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1634         if ( IS_ERR(sg_sysfs_class) ) {
1635                 rc = PTR_ERR(sg_sysfs_class);
1636                 goto err_out;
1637         }
1638         sg_sysfs_valid = 1;
1639         rc = scsi_register_interface(&sg_interface);
1640         if (0 == rc) {
1641 #ifdef CONFIG_SCSI_PROC_FS
1642                 sg_proc_init();
1643 #endif                          /* CONFIG_SCSI_PROC_FS */
1644                 return 0;
1645         }
1646         class_destroy(sg_sysfs_class);
1647 err_out:
1648         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1649         return rc;
1650 }
1651
1652 static void __exit
1653 exit_sg(void)
1654 {
1655 #ifdef CONFIG_SCSI_PROC_FS
1656         sg_proc_cleanup();
1657 #endif                          /* CONFIG_SCSI_PROC_FS */
1658         scsi_unregister_interface(&sg_interface);
1659         class_destroy(sg_sysfs_class);
1660         sg_sysfs_valid = 0;
1661         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1662                                  SG_MAX_DEVS);
1663         idr_destroy(&sg_index_idr);
1664 }
1665
1666 static int
1667 sg_start_req(Sg_request *srp, unsigned char *cmd)
1668 {
1669         int res;
1670         struct request *rq;
1671         Sg_fd *sfp = srp->parentfp;
1672         sg_io_hdr_t *hp = &srp->header;
1673         int dxfer_len = (int) hp->dxfer_len;
1674         int dxfer_dir = hp->dxfer_direction;
1675         unsigned int iov_count = hp->iovec_count;
1676         Sg_scatter_hold *req_schp = &srp->data;
1677         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1678         struct request_queue *q = sfp->parentdp->device->request_queue;
1679         struct rq_map_data *md, map_data;
1680         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1681         unsigned char *long_cmdp = NULL;
1682
1683         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1684                                       "sg_start_req: dxfer_len=%d\n",
1685                                       dxfer_len));
1686
1687         if (hp->cmd_len > BLK_MAX_CDB) {
1688                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1689                 if (!long_cmdp)
1690                         return -ENOMEM;
1691         }
1692
1693         /*
1694          * NOTE
1695          *
1696          * With scsi-mq enabled, there are a fixed number of preallocated
1697          * requests equal in number to shost->can_queue.  If all of the
1698          * preallocated requests are already in use, then using GFP_ATOMIC with
1699          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1700          * will cause blk_get_request() to sleep until an active command
1701          * completes, freeing up a request.  Neither option is ideal, but
1702          * GFP_KERNEL is the better choice to prevent userspace from getting an
1703          * unexpected EWOULDBLOCK.
1704          *
1705          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1706          * does not sleep except under memory pressure.
1707          */
1708         rq = blk_get_request(q, rw, GFP_KERNEL);
1709         if (IS_ERR(rq)) {
1710                 kfree(long_cmdp);
1711                 return PTR_ERR(rq);
1712         }
1713
1714         blk_rq_set_block_pc(rq);
1715
1716         if (hp->cmd_len > BLK_MAX_CDB)
1717                 rq->cmd = long_cmdp;
1718         memcpy(rq->cmd, cmd, hp->cmd_len);
1719         rq->cmd_len = hp->cmd_len;
1720
1721         srp->rq = rq;
1722         rq->end_io_data = srp;
1723         rq->sense = srp->sense_b;
1724         rq->retries = SG_DEFAULT_RETRIES;
1725
1726         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1727                 return 0;
1728
1729         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1730             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1731             !sfp->parentdp->device->host->unchecked_isa_dma &&
1732             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1733                 md = NULL;
1734         else
1735                 md = &map_data;
1736
1737         if (md) {
1738                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1739                         sg_link_reserve(sfp, srp, dxfer_len);
1740                 else {
1741                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1742                         if (res)
1743                                 return res;
1744                 }
1745
1746                 md->pages = req_schp->pages;
1747                 md->page_order = req_schp->page_order;
1748                 md->nr_entries = req_schp->k_use_sg;
1749                 md->offset = 0;
1750                 md->null_mapped = hp->dxferp ? 0 : 1;
1751                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1752                         md->from_user = 1;
1753                 else
1754                         md->from_user = 0;
1755         }
1756
1757         if (iov_count) {
1758                 struct iovec *iov = NULL;
1759                 struct iov_iter i;
1760
1761                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1762                 if (res < 0)
1763                         return res;
1764
1765                 iov_iter_truncate(&i, hp->dxfer_len);
1766
1767                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1768                 kfree(iov);
1769         } else
1770                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1771                                       hp->dxfer_len, GFP_ATOMIC);
1772
1773         if (!res) {
1774                 srp->bio = rq->bio;
1775
1776                 if (!md) {
1777                         req_schp->dio_in_use = 1;
1778                         hp->info |= SG_INFO_DIRECT_IO;
1779                 }
1780         }
1781         return res;
1782 }
1783
1784 static int
1785 sg_finish_rem_req(Sg_request *srp)
1786 {
1787         int ret = 0;
1788
1789         Sg_fd *sfp = srp->parentfp;
1790         Sg_scatter_hold *req_schp = &srp->data;
1791
1792         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1793                                       "sg_finish_rem_req: res_used=%d\n",
1794                                       (int) srp->res_used));
1795         if (srp->bio)
1796                 ret = blk_rq_unmap_user(srp->bio);
1797
1798         if (srp->rq) {
1799                 if (srp->rq->cmd != srp->rq->__cmd)
1800                         kfree(srp->rq->cmd);
1801                 blk_put_request(srp->rq);
1802         }
1803
1804         if (srp->res_used)
1805                 sg_unlink_reserve(sfp, srp);
1806         else
1807                 sg_remove_scat(sfp, req_schp);
1808
1809         sg_remove_request(sfp, srp);
1810
1811         return ret;
1812 }
1813
1814 static int
1815 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1816 {
1817         int sg_bufflen = tablesize * sizeof(struct page *);
1818         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1819
1820         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1821         if (!schp->pages)
1822                 return -ENOMEM;
1823         schp->sglist_len = sg_bufflen;
1824         return tablesize;       /* number of scat_gath elements allocated */
1825 }
1826
1827 static int
1828 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1829 {
1830         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1831         int sg_tablesize = sfp->parentdp->sg_tablesize;
1832         int blk_size = buff_size, order;
1833         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1834
1835         if (blk_size < 0)
1836                 return -EFAULT;
1837         if (0 == blk_size)
1838                 ++blk_size;     /* don't know why */
1839         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1840         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1841         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1842                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1843                 buff_size, blk_size));
1844
1845         /* N.B. ret_sz carried into this block ... */
1846         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1847         if (mx_sc_elems < 0)
1848                 return mx_sc_elems;     /* most likely -ENOMEM */
1849
1850         num = scatter_elem_sz;
1851         if (unlikely(num != scatter_elem_sz_prev)) {
1852                 if (num < PAGE_SIZE) {
1853                         scatter_elem_sz = PAGE_SIZE;
1854                         scatter_elem_sz_prev = PAGE_SIZE;
1855                 } else
1856                         scatter_elem_sz_prev = num;
1857         }
1858
1859         if (sfp->low_dma)
1860                 gfp_mask |= GFP_DMA;
1861
1862         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1863                 gfp_mask |= __GFP_ZERO;
1864
1865         order = get_order(num);
1866 retry:
1867         ret_sz = 1 << (PAGE_SHIFT + order);
1868
1869         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1870              k++, rem_sz -= ret_sz) {
1871
1872                 num = (rem_sz > scatter_elem_sz_prev) ?
1873                         scatter_elem_sz_prev : rem_sz;
1874
1875                 schp->pages[k] = alloc_pages(gfp_mask, order);
1876                 if (!schp->pages[k])
1877                         goto out;
1878
1879                 if (num == scatter_elem_sz_prev) {
1880                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1881                                 scatter_elem_sz = ret_sz;
1882                                 scatter_elem_sz_prev = ret_sz;
1883                         }
1884                 }
1885
1886                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1887                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1888                                  k, num, ret_sz));
1889         }               /* end of for loop */
1890
1891         schp->page_order = order;
1892         schp->k_use_sg = k;
1893         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1894                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1895                          k, rem_sz));
1896
1897         schp->bufflen = blk_size;
1898         if (rem_sz > 0) /* must have failed */
1899                 return -ENOMEM;
1900         return 0;
1901 out:
1902         for (i = 0; i < k; i++)
1903                 __free_pages(schp->pages[i], order);
1904
1905         if (--order >= 0)
1906                 goto retry;
1907
1908         return -ENOMEM;
1909 }
1910
1911 static void
1912 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1913 {
1914         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1915                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1916         if (schp->pages && schp->sglist_len > 0) {
1917                 if (!schp->dio_in_use) {
1918                         int k;
1919
1920                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1921                                 SCSI_LOG_TIMEOUT(5,
1922                                         sg_printk(KERN_INFO, sfp->parentdp,
1923                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1924                                         k, schp->pages[k]));
1925                                 __free_pages(schp->pages[k], schp->page_order);
1926                         }
1927
1928                         kfree(schp->pages);
1929                 }
1930         }
1931         memset(schp, 0, sizeof (*schp));
1932 }
1933
1934 static int
1935 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1936 {
1937         Sg_scatter_hold *schp = &srp->data;
1938         int k, num;
1939
1940         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1941                          "sg_read_oxfer: num_read_xfer=%d\n",
1942                          num_read_xfer));
1943         if ((!outp) || (num_read_xfer <= 0))
1944                 return 0;
1945
1946         num = 1 << (PAGE_SHIFT + schp->page_order);
1947         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1948                 if (num > num_read_xfer) {
1949                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1950                                            num_read_xfer))
1951                                 return -EFAULT;
1952                         break;
1953                 } else {
1954                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1955                                            num))
1956                                 return -EFAULT;
1957                         num_read_xfer -= num;
1958                         if (num_read_xfer <= 0)
1959                                 break;
1960                         outp += num;
1961                 }
1962         }
1963
1964         return 0;
1965 }
1966
1967 static void
1968 sg_build_reserve(Sg_fd * sfp, int req_size)
1969 {
1970         Sg_scatter_hold *schp = &sfp->reserve;
1971
1972         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1973                          "sg_build_reserve: req_size=%d\n", req_size));
1974         do {
1975                 if (req_size < PAGE_SIZE)
1976                         req_size = PAGE_SIZE;
1977                 if (0 == sg_build_indirect(schp, sfp, req_size))
1978                         return;
1979                 else
1980                         sg_remove_scat(sfp, schp);
1981                 req_size >>= 1; /* divide by 2 */
1982         } while (req_size > (PAGE_SIZE / 2));
1983 }
1984
1985 static void
1986 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1987 {
1988         Sg_scatter_hold *req_schp = &srp->data;
1989         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1990         int k, num, rem;
1991
1992         srp->res_used = 1;
1993         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1994                          "sg_link_reserve: size=%d\n", size));
1995         rem = size;
1996
1997         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1998         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1999                 if (rem <= num) {
2000                         req_schp->k_use_sg = k + 1;
2001                         req_schp->sglist_len = rsv_schp->sglist_len;
2002                         req_schp->pages = rsv_schp->pages;
2003
2004                         req_schp->bufflen = size;
2005                         req_schp->page_order = rsv_schp->page_order;
2006                         break;
2007                 } else
2008                         rem -= num;
2009         }
2010
2011         if (k >= rsv_schp->k_use_sg)
2012                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2013                                  "sg_link_reserve: BAD size\n"));
2014 }
2015
2016 static void
2017 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2018 {
2019         Sg_scatter_hold *req_schp = &srp->data;
2020
2021         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2022                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2023                                       (int) req_schp->k_use_sg));
2024         req_schp->k_use_sg = 0;
2025         req_schp->bufflen = 0;
2026         req_schp->pages = NULL;
2027         req_schp->page_order = 0;
2028         req_schp->sglist_len = 0;
2029         sfp->save_scat_len = 0;
2030         srp->res_used = 0;
2031 }
2032
2033 static Sg_request *
2034 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2035 {
2036         Sg_request *resp;
2037         unsigned long iflags;
2038
2039         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2040         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2041                 /* look for requests that are ready + not SG_IO owned */
2042                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2043                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2044                         resp->done = 2; /* guard against other readers */
2045                         break;
2046                 }
2047         }
2048         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2049         return resp;
2050 }
2051
2052 /* always adds to end of list */
2053 static Sg_request *
2054 sg_add_request(Sg_fd * sfp)
2055 {
2056         int k;
2057         unsigned long iflags;
2058         Sg_request *resp;
2059         Sg_request *rp = sfp->req_arr;
2060
2061         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2062         resp = sfp->headrp;
2063         if (!resp) {
2064                 memset(rp, 0, sizeof (Sg_request));
2065                 rp->parentfp = sfp;
2066                 resp = rp;
2067                 sfp->headrp = resp;
2068         } else {
2069                 if (0 == sfp->cmd_q)
2070                         resp = NULL;    /* command queuing disallowed */
2071                 else {
2072                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2073                                 if (!rp->parentfp)
2074                                         break;
2075                         }
2076                         if (k < SG_MAX_QUEUE) {
2077                                 memset(rp, 0, sizeof (Sg_request));
2078                                 rp->parentfp = sfp;
2079                                 while (resp->nextrp)
2080                                         resp = resp->nextrp;
2081                                 resp->nextrp = rp;
2082                                 resp = rp;
2083                         } else
2084                                 resp = NULL;
2085                 }
2086         }
2087         if (resp) {
2088                 resp->nextrp = NULL;
2089                 resp->header.duration = jiffies_to_msecs(jiffies);
2090         }
2091         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2092         return resp;
2093 }
2094
2095 /* Return of 1 for found; 0 for not found */
2096 static int
2097 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2098 {
2099         Sg_request *prev_rp;
2100         Sg_request *rp;
2101         unsigned long iflags;
2102         int res = 0;
2103
2104         if ((!sfp) || (!srp) || (!sfp->headrp))
2105                 return res;
2106         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2107         prev_rp = sfp->headrp;
2108         if (srp == prev_rp) {
2109                 sfp->headrp = prev_rp->nextrp;
2110                 prev_rp->parentfp = NULL;
2111                 res = 1;
2112         } else {
2113                 while ((rp = prev_rp->nextrp)) {
2114                         if (srp == rp) {
2115                                 prev_rp->nextrp = rp->nextrp;
2116                                 rp->parentfp = NULL;
2117                                 res = 1;
2118                                 break;
2119                         }
2120                         prev_rp = rp;
2121                 }
2122         }
2123         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2124         return res;
2125 }
2126
2127 static Sg_fd *
2128 sg_add_sfp(Sg_device * sdp)
2129 {
2130         Sg_fd *sfp;
2131         unsigned long iflags;
2132         int bufflen;
2133
2134         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2135         if (!sfp)
2136                 return ERR_PTR(-ENOMEM);
2137
2138         init_waitqueue_head(&sfp->read_wait);
2139         rwlock_init(&sfp->rq_list_lock);
2140
2141         kref_init(&sfp->f_ref);
2142         sfp->timeout = SG_DEFAULT_TIMEOUT;
2143         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2144         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2145         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2146             sdp->device->host->unchecked_isa_dma : 1;
2147         sfp->cmd_q = SG_DEF_COMMAND_Q;
2148         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2149         sfp->parentdp = sdp;
2150         write_lock_irqsave(&sdp->sfd_lock, iflags);
2151         if (atomic_read(&sdp->detaching)) {
2152                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2153                 return ERR_PTR(-ENODEV);
2154         }
2155         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2156         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2157         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2158                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2159         if (unlikely(sg_big_buff != def_reserved_size))
2160                 sg_big_buff = def_reserved_size;
2161
2162         bufflen = min_t(int, sg_big_buff,
2163                         max_sectors_bytes(sdp->device->request_queue));
2164         sg_build_reserve(sfp, bufflen);
2165         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2166                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2167                                       sfp->reserve.bufflen,
2168                                       sfp->reserve.k_use_sg));
2169
2170         kref_get(&sdp->d_ref);
2171         __module_get(THIS_MODULE);
2172         return sfp;
2173 }
2174
2175 static void
2176 sg_remove_sfp_usercontext(struct work_struct *work)
2177 {
2178         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2179         struct sg_device *sdp = sfp->parentdp;
2180
2181         /* Cleanup any responses which were never read(). */
2182         while (sfp->headrp)
2183                 sg_finish_rem_req(sfp->headrp);
2184
2185         if (sfp->reserve.bufflen > 0) {
2186                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2187                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2188                                 (int) sfp->reserve.bufflen,
2189                                 (int) sfp->reserve.k_use_sg));
2190                 sg_remove_scat(sfp, &sfp->reserve);
2191         }
2192
2193         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2194                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2195         kfree(sfp);
2196
2197         scsi_device_put(sdp->device);
2198         kref_put(&sdp->d_ref, sg_device_destroy);
2199         module_put(THIS_MODULE);
2200 }
2201
2202 static void
2203 sg_remove_sfp(struct kref *kref)
2204 {
2205         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2206         struct sg_device *sdp = sfp->parentdp;
2207         unsigned long iflags;
2208
2209         write_lock_irqsave(&sdp->sfd_lock, iflags);
2210         list_del(&sfp->sfd_siblings);
2211         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2212
2213         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2214         schedule_work(&sfp->ew.work);
2215 }
2216
2217 static int
2218 sg_res_in_use(Sg_fd * sfp)
2219 {
2220         const Sg_request *srp;
2221         unsigned long iflags;
2222
2223         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2224         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2225                 if (srp->res_used)
2226                         break;
2227         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2228         return srp ? 1 : 0;
2229 }
2230
2231 #ifdef CONFIG_SCSI_PROC_FS
2232 static int
2233 sg_idr_max_id(int id, void *p, void *data)
2234 {
2235         int *k = data;
2236
2237         if (*k < id)
2238                 *k = id;
2239
2240         return 0;
2241 }
2242
2243 static int
2244 sg_last_dev(void)
2245 {
2246         int k = -1;
2247         unsigned long iflags;
2248
2249         read_lock_irqsave(&sg_index_lock, iflags);
2250         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2251         read_unlock_irqrestore(&sg_index_lock, iflags);
2252         return k + 1;           /* origin 1 */
2253 }
2254 #endif
2255
2256 /* must be called with sg_index_lock held */
2257 static Sg_device *sg_lookup_dev(int dev)
2258 {
2259         return idr_find(&sg_index_idr, dev);
2260 }
2261
2262 static Sg_device *
2263 sg_get_dev(int dev)
2264 {
2265         struct sg_device *sdp;
2266         unsigned long flags;
2267
2268         read_lock_irqsave(&sg_index_lock, flags);
2269         sdp = sg_lookup_dev(dev);
2270         if (!sdp)
2271                 sdp = ERR_PTR(-ENXIO);
2272         else if (atomic_read(&sdp->detaching)) {
2273                 /* If sdp->detaching, then the refcount may already be 0, in
2274                  * which case it would be a bug to do kref_get().
2275                  */
2276                 sdp = ERR_PTR(-ENODEV);
2277         } else
2278                 kref_get(&sdp->d_ref);
2279         read_unlock_irqrestore(&sg_index_lock, flags);
2280
2281         return sdp;
2282 }
2283
2284 #ifdef CONFIG_SCSI_PROC_FS
2285
2286 static struct proc_dir_entry *sg_proc_sgp = NULL;
2287
2288 static char sg_proc_sg_dirname[] = "scsi/sg";
2289
2290 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2291
2292 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2293 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2294                                   size_t count, loff_t *off);
2295 static const struct file_operations adio_fops = {
2296         .owner = THIS_MODULE,
2297         .open = sg_proc_single_open_adio,
2298         .read = seq_read,
2299         .llseek = seq_lseek,
2300         .write = sg_proc_write_adio,
2301         .release = single_release,
2302 };
2303
2304 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2305 static ssize_t sg_proc_write_dressz(struct file *filp,
2306                 const char __user *buffer, size_t count, loff_t *off);
2307 static const struct file_operations dressz_fops = {
2308         .owner = THIS_MODULE,
2309         .open = sg_proc_single_open_dressz,
2310         .read = seq_read,
2311         .llseek = seq_lseek,
2312         .write = sg_proc_write_dressz,
2313         .release = single_release,
2314 };
2315
2316 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2317 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2318 static const struct file_operations version_fops = {
2319         .owner = THIS_MODULE,
2320         .open = sg_proc_single_open_version,
2321         .read = seq_read,
2322         .llseek = seq_lseek,
2323         .release = single_release,
2324 };
2325
2326 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2327 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2328 static const struct file_operations devhdr_fops = {
2329         .owner = THIS_MODULE,
2330         .open = sg_proc_single_open_devhdr,
2331         .read = seq_read,
2332         .llseek = seq_lseek,
2333         .release = single_release,
2334 };
2335
2336 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2337 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2338 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2339 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2340 static void dev_seq_stop(struct seq_file *s, void *v);
2341 static const struct file_operations dev_fops = {
2342         .owner = THIS_MODULE,
2343         .open = sg_proc_open_dev,
2344         .read = seq_read,
2345         .llseek = seq_lseek,
2346         .release = seq_release,
2347 };
2348 static const struct seq_operations dev_seq_ops = {
2349         .start = dev_seq_start,
2350         .next  = dev_seq_next,
2351         .stop  = dev_seq_stop,
2352         .show  = sg_proc_seq_show_dev,
2353 };
2354
2355 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2356 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2357 static const struct file_operations devstrs_fops = {
2358         .owner = THIS_MODULE,
2359         .open = sg_proc_open_devstrs,
2360         .read = seq_read,
2361         .llseek = seq_lseek,
2362         .release = seq_release,
2363 };
2364 static const struct seq_operations devstrs_seq_ops = {
2365         .start = dev_seq_start,
2366         .next  = dev_seq_next,
2367         .stop  = dev_seq_stop,
2368         .show  = sg_proc_seq_show_devstrs,
2369 };
2370
2371 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2372 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2373 static const struct file_operations debug_fops = {
2374         .owner = THIS_MODULE,
2375         .open = sg_proc_open_debug,
2376         .read = seq_read,
2377         .llseek = seq_lseek,
2378         .release = seq_release,
2379 };
2380 static const struct seq_operations debug_seq_ops = {
2381         .start = dev_seq_start,
2382         .next  = dev_seq_next,
2383         .stop  = dev_seq_stop,
2384         .show  = sg_proc_seq_show_debug,
2385 };
2386
2387
2388 struct sg_proc_leaf {
2389         const char * name;
2390         const struct file_operations * fops;
2391 };
2392
2393 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2394         {"allow_dio", &adio_fops},
2395         {"debug", &debug_fops},
2396         {"def_reserved_size", &dressz_fops},
2397         {"device_hdr", &devhdr_fops},
2398         {"devices", &dev_fops},
2399         {"device_strs", &devstrs_fops},
2400         {"version", &version_fops}
2401 };
2402
2403 static int
2404 sg_proc_init(void)
2405 {
2406         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2407         int k;
2408
2409         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2410         if (!sg_proc_sgp)
2411                 return 1;
2412         for (k = 0; k < num_leaves; ++k) {
2413                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2414                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2415                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2416         }
2417         return 0;
2418 }
2419
2420 static void
2421 sg_proc_cleanup(void)
2422 {
2423         int k;
2424         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2425
2426         if (!sg_proc_sgp)
2427                 return;
2428         for (k = 0; k < num_leaves; ++k)
2429                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2430         remove_proc_entry(sg_proc_sg_dirname, NULL);
2431 }
2432
2433
2434 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2435 {
2436         seq_printf(s, "%d\n", *((int *)s->private));
2437         return 0;
2438 }
2439
2440 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2441 {
2442         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2443 }
2444
2445 static ssize_t
2446 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2447                    size_t count, loff_t *off)
2448 {
2449         int err;
2450         unsigned long num;
2451
2452         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2453                 return -EACCES;
2454         err = kstrtoul_from_user(buffer, count, 0, &num);
2455         if (err)
2456                 return err;
2457         sg_allow_dio = num ? 1 : 0;
2458         return count;
2459 }
2460
2461 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2462 {
2463         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2464 }
2465
2466 static ssize_t
2467 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2468                      size_t count, loff_t *off)
2469 {
2470         int err;
2471         unsigned long k = ULONG_MAX;
2472
2473         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2474                 return -EACCES;
2475
2476         err = kstrtoul_from_user(buffer, count, 0, &k);
2477         if (err)
2478                 return err;
2479         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2480                 sg_big_buff = k;
2481                 return count;
2482         }
2483         return -ERANGE;
2484 }
2485
2486 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2487 {
2488         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2489                    sg_version_date);
2490         return 0;
2491 }
2492
2493 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2494 {
2495         return single_open(file, sg_proc_seq_show_version, NULL);
2496 }
2497
2498 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2499 {
2500         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2501         return 0;
2502 }
2503
2504 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2505 {
2506         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2507 }
2508
2509 struct sg_proc_deviter {
2510         loff_t  index;
2511         size_t  max;
2512 };
2513
2514 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2515 {
2516         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2517
2518         s->private = it;
2519         if (! it)
2520                 return NULL;
2521
2522         it->index = *pos;
2523         it->max = sg_last_dev();
2524         if (it->index >= it->max)
2525                 return NULL;
2526         return it;
2527 }
2528
2529 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2530 {
2531         struct sg_proc_deviter * it = s->private;
2532
2533         *pos = ++it->index;
2534         return (it->index < it->max) ? it : NULL;
2535 }
2536
2537 static void dev_seq_stop(struct seq_file *s, void *v)
2538 {
2539         kfree(s->private);
2540 }
2541
2542 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2543 {
2544         return seq_open(file, &dev_seq_ops);
2545 }
2546
2547 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2548 {
2549         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2550         Sg_device *sdp;
2551         struct scsi_device *scsidp;
2552         unsigned long iflags;
2553
2554         read_lock_irqsave(&sg_index_lock, iflags);
2555         sdp = it ? sg_lookup_dev(it->index) : NULL;
2556         if ((NULL == sdp) || (NULL == sdp->device) ||
2557             (atomic_read(&sdp->detaching)))
2558                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2559         else {
2560                 scsidp = sdp->device;
2561                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2562                               scsidp->host->host_no, scsidp->channel,
2563                               scsidp->id, scsidp->lun, (int) scsidp->type,
2564                               1,
2565                               (int) scsidp->queue_depth,
2566                               (int) atomic_read(&scsidp->device_busy),
2567                               (int) scsi_device_online(scsidp));
2568         }
2569         read_unlock_irqrestore(&sg_index_lock, iflags);
2570         return 0;
2571 }
2572
2573 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2574 {
2575         return seq_open(file, &devstrs_seq_ops);
2576 }
2577
2578 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2579 {
2580         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2581         Sg_device *sdp;
2582         struct scsi_device *scsidp;
2583         unsigned long iflags;
2584
2585         read_lock_irqsave(&sg_index_lock, iflags);
2586         sdp = it ? sg_lookup_dev(it->index) : NULL;
2587         scsidp = sdp ? sdp->device : NULL;
2588         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2589                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2590                            scsidp->vendor, scsidp->model, scsidp->rev);
2591         else
2592                 seq_puts(s, "<no active device>\n");
2593         read_unlock_irqrestore(&sg_index_lock, iflags);
2594         return 0;
2595 }
2596
2597 /* must be called while holding sg_index_lock */
2598 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2599 {
2600         int k, m, new_interface, blen, usg;
2601         Sg_request *srp;
2602         Sg_fd *fp;
2603         const sg_io_hdr_t *hp;
2604         const char * cp;
2605         unsigned int ms;
2606
2607         k = 0;
2608         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2609                 k++;
2610                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2611                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2612                            "(res)sgat=%d low_dma=%d\n", k,
2613                            jiffies_to_msecs(fp->timeout),
2614                            fp->reserve.bufflen,
2615                            (int) fp->reserve.k_use_sg,
2616                            (int) fp->low_dma);
2617                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2618                            (int) fp->cmd_q, (int) fp->force_packid,
2619                            (int) fp->keep_orphan);
2620                 for (m = 0, srp = fp->headrp;
2621                                 srp != NULL;
2622                                 ++m, srp = srp->nextrp) {
2623                         hp = &srp->header;
2624                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2625                         if (srp->res_used) {
2626                                 if (new_interface &&
2627                                     (SG_FLAG_MMAP_IO & hp->flags))
2628                                         cp = "     mmap>> ";
2629                                 else
2630                                         cp = "     rb>> ";
2631                         } else {
2632                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2633                                         cp = "     dio>> ";
2634                                 else
2635                                         cp = "     ";
2636                         }
2637                         seq_puts(s, cp);
2638                         blen = srp->data.bufflen;
2639                         usg = srp->data.k_use_sg;
2640                         seq_puts(s, srp->done ?
2641                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2642                                   : "act:");
2643                         seq_printf(s, " id=%d blen=%d",
2644                                    srp->header.pack_id, blen);
2645                         if (srp->done)
2646                                 seq_printf(s, " dur=%d", hp->duration);
2647                         else {
2648                                 ms = jiffies_to_msecs(jiffies);
2649                                 seq_printf(s, " t_o/elap=%d/%d",
2650                                         (new_interface ? hp->timeout :
2651                                                   jiffies_to_msecs(fp->timeout)),
2652                                         (ms > hp->duration ? ms - hp->duration : 0));
2653                         }
2654                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2655                                    (int) srp->data.cmd_opcode);
2656                 }
2657                 if (0 == m)
2658                         seq_puts(s, "     No requests active\n");
2659                 read_unlock(&fp->rq_list_lock);
2660         }
2661 }
2662
2663 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2664 {
2665         return seq_open(file, &debug_seq_ops);
2666 }
2667
2668 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2669 {
2670         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2671         Sg_device *sdp;
2672         unsigned long iflags;
2673
2674         if (it && (0 == it->index))
2675                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2676                            (int)it->max, sg_big_buff);
2677
2678         read_lock_irqsave(&sg_index_lock, iflags);
2679         sdp = it ? sg_lookup_dev(it->index) : NULL;
2680         if (NULL == sdp)
2681                 goto skip;
2682         read_lock(&sdp->sfd_lock);
2683         if (!list_empty(&sdp->sfds)) {
2684                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2685                 if (atomic_read(&sdp->detaching))
2686                         seq_puts(s, "detaching pending close ");
2687                 else if (sdp->device) {
2688                         struct scsi_device *scsidp = sdp->device;
2689
2690                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2691                                    scsidp->host->host_no,
2692                                    scsidp->channel, scsidp->id,
2693                                    scsidp->lun,
2694                                    scsidp->host->hostt->emulated);
2695                 }
2696                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2697                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2698                 sg_proc_debug_helper(s, sdp);
2699         }
2700         read_unlock(&sdp->sfd_lock);
2701 skip:
2702         read_unlock_irqrestore(&sg_index_lock, iflags);
2703         return 0;
2704 }
2705
2706 #endif                          /* CONFIG_SCSI_PROC_FS */
2707
2708 module_init(init_sg);
2709 module_exit(exit_sg);