drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct list_head entry; /* list entry */
 126         struct sg_fd *parentfp; /* NULL -> not in use */
 127         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 128         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 129         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 131         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 132         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 133         /* done protected by rq_list_lock */
 134         char done;              /* 0->before bh, 1->before read, 2->read */
 135         struct request *rq;
 136         struct bio *bio;
 137         struct execute_work ew;
 138 } Sg_request;
 139
 140 typedef struct sg_fd {          /* holds the state of a file descriptor */
 141         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142         struct sg_device *parentdp;     /* owning device */
 143         wait_queue_head_t read_wait;    /* queue read until command done */
 144         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 145         struct mutex f_mutex;   /* protect against changes in this fd */
 146         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 147         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 148         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 149         struct list_head rq_list; /* head of request list */
 150         struct fasync_struct *async_qp; /* used by asynchronous notification */
 151         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 153         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 154         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 155         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 156         char mmap_called;       /* 0 -> mmap() never called on this fd */
 157         char res_in_use;        /* 1 -> 'reserve' array in use */
 158         struct kref f_ref;
 159         struct execute_work ew;
 160 } Sg_fd;
 161
 162 typedef struct sg_device { /* holds the state of each scsi generic device */
 163         struct scsi_device *device;
 164         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165         struct mutex open_rel_lock;     /* held when in open() or release() */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         struct list_head sfds;
 169         rwlock_t sfd_lock;      /* protect access to sfd list */
 170         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 172         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static int sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static Sg_device *sg_get_dev(int dev);
 202 static void sg_device_destroy(struct kref *kref);
 203
 204 #define SZ_SG_HEADER sizeof(struct sg_header)
 205 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 206 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 207 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 208
 209 #define sg_printk(prefix, sdp, fmt, a...) \
 210         sdev_prefix_printk(prefix, (sdp)->device,               \
 211                            (sdp)->disk->disk_name, fmt, ##a)
 212
 213 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 214 {
 215         struct sg_fd *sfp = filp->private_data;
 216
 217         if (sfp->parentdp->device->type == TYPE_SCANNER)
 218                 return 0;
 219
 220         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 221 }
 222
 223 static int
 224 open_wait(Sg_device *sdp, int flags)
 225 {
 226         int retval = 0;
 227
 228         if (flags & O_EXCL) {
 229                 while (sdp->open_cnt > 0) {
 230                         mutex_unlock(&sdp->open_rel_lock);
 231                         retval = wait_event_interruptible(sdp->open_wait,
 232                                         (atomic_read(&sdp->detaching) ||
 233                                          !sdp->open_cnt));
 234                         mutex_lock(&sdp->open_rel_lock);
 235
 236                         if (retval) /* -ERESTARTSYS */
 237                                 return retval;
 238                         if (atomic_read(&sdp->detaching))
 239                                 return -ENODEV;
 240                 }
 241         } else {
 242                 while (sdp->exclude) {
 243                         mutex_unlock(&sdp->open_rel_lock);
 244                         retval = wait_event_interruptible(sdp->open_wait,
 245                                         (atomic_read(&sdp->detaching) ||
 246                                          !sdp->exclude));
 247                         mutex_lock(&sdp->open_rel_lock);
 248
 249                         if (retval) /* -ERESTARTSYS */
 250                                 return retval;
 251                         if (atomic_read(&sdp->detaching))
 252                                 return -ENODEV;
 253                 }
 254         }
 255
 256         return retval;
 257 }
 258
 259 /* Returns 0 on success, else a negated errno value */
 260 static int
 261 sg_open(struct inode *inode, struct file *filp)
 262 {
 263         int dev = iminor(inode);
 264         int flags = filp->f_flags;
 265         struct request_queue *q;
 266         Sg_device *sdp;
 267         Sg_fd *sfp;
 268         int retval;
 269
 270         nonseekable_open(inode, filp);
 271         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 272                 return -EPERM; /* Can't lock it with read only access */
 273         sdp = sg_get_dev(dev);
 274         if (IS_ERR(sdp))
 275                 return PTR_ERR(sdp);
 276
 277         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 278                                       "sg_open: flags=0x%x\n", flags));
 279
 280         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 281         /* Prevent the device driver from vanishing while we sleep */
 282         retval = scsi_device_get(sdp->device);
 283         if (retval)
 284                 goto sg_put;
 285
 286         retval = scsi_autopm_get_device(sdp->device);
 287         if (retval)
 288                 goto sdp_put;
 289
 290         /* scsi_block_when_processing_errors() may block so bypass
 291          * check if O_NONBLOCK. Permits SCSI commands to be issued
 292          * during error recovery. Tread carefully. */
 293         if (!((flags & O_NONBLOCK) ||
 294               scsi_block_when_processing_errors(sdp->device))) {
 295                 retval = -ENXIO;
 296                 /* we are in error recovery for this device */
 297                 goto error_out;
 298         }
 299
 300         mutex_lock(&sdp->open_rel_lock);
 301         if (flags & O_NONBLOCK) {
 302                 if (flags & O_EXCL) {
 303                         if (sdp->open_cnt > 0) {
 304                                 retval = -EBUSY;
 305                                 goto error_mutex_locked;
 306                         }
 307                 } else {
 308                         if (sdp->exclude) {
 309                                 retval = -EBUSY;
 310                                 goto error_mutex_locked;
 311                         }
 312                 }
 313         } else {
 314                 retval = open_wait(sdp, flags);
 315                 if (retval) /* -ERESTARTSYS or -ENODEV */
 316                         goto error_mutex_locked;
 317         }
 318
 319         /* N.B. at this point we are holding the open_rel_lock */
 320         if (flags & O_EXCL)
 321                 sdp->exclude = true;
 322
 323         if (sdp->open_cnt < 1) {  /* no existing opens */
 324                 sdp->sgdebug = 0;
 325                 q = sdp->device->request_queue;
 326                 sdp->sg_tablesize = queue_max_segments(q);
 327         }
 328         sfp = sg_add_sfp(sdp);
 329         if (IS_ERR(sfp)) {
 330                 retval = PTR_ERR(sfp);
 331                 goto out_undo;
 332         }
 333
 334         filp->private_data = sfp;
 335         sdp->open_cnt++;
 336         mutex_unlock(&sdp->open_rel_lock);
 337
 338         retval = 0;
 339 sg_put:
 340         kref_put(&sdp->d_ref, sg_device_destroy);
 341         return retval;
 342
 343 out_undo:
 344         if (flags & O_EXCL) {
 345                 sdp->exclude = false;   /* undo if error */
 346                 wake_up_interruptible(&sdp->open_wait);
 347         }
 348 error_mutex_locked:
 349         mutex_unlock(&sdp->open_rel_lock);
 350 error_out:
 351         scsi_autopm_put_device(sdp->device);
 352 sdp_put:
 353         scsi_device_put(sdp->device);
 354         goto sg_put;
 355 }
 356
 357 /* Release resources associated with a successful sg_open()
 358  * Returns 0 on success, else a negated errno value */
 359 static int
 360 sg_release(struct inode *inode, struct file *filp)
 361 {
 362         Sg_device *sdp;
 363         Sg_fd *sfp;
 364
 365         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 366                 return -ENXIO;
 367         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 368
 369         mutex_lock(&sdp->open_rel_lock);
 370         scsi_autopm_put_device(sdp->device);
 371         kref_put(&sfp->f_ref, sg_remove_sfp);
 372         sdp->open_cnt--;
 373
 374         /* possibly many open()s waiting on exlude clearing, start many;
 375          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 376         if (sdp->exclude) {
 377                 sdp->exclude = false;
 378                 wake_up_interruptible_all(&sdp->open_wait);
 379         } else if (0 == sdp->open_cnt) {
 380                 wake_up_interruptible(&sdp->open_wait);
 381         }
 382         mutex_unlock(&sdp->open_rel_lock);
 383         return 0;
 384 }
 385
 386 static ssize_t
 387 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 388 {
 389         Sg_device *sdp;
 390         Sg_fd *sfp;
 391         Sg_request *srp;
 392         int req_pack_id = -1;
 393         sg_io_hdr_t *hp;
 394         struct sg_header *old_hdr = NULL;
 395         int retval = 0;
 396
 397         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 398                 return -ENXIO;
 399         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 400                                       "sg_read: count=%d\n", (int) count));
 401
 402         if (!access_ok(VERIFY_WRITE, buf, count))
 403                 return -EFAULT;
 404         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 405                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 406                 if (!old_hdr)
 407                         return -ENOMEM;
 408                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 409                         retval = -EFAULT;
 410                         goto free_old_hdr;
 411                 }
 412                 if (old_hdr->reply_len < 0) {
 413                         if (count >= SZ_SG_IO_HDR) {
 414                                 sg_io_hdr_t *new_hdr;
 415                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 416                                 if (!new_hdr) {
 417                                         retval = -ENOMEM;
 418                                         goto free_old_hdr;
 419                                 }
 420                                 retval =__copy_from_user
 421                                     (new_hdr, buf, SZ_SG_IO_HDR);
 422                                 req_pack_id = new_hdr->pack_id;
 423                                 kfree(new_hdr);
 424                                 if (retval) {
 425                                         retval = -EFAULT;
 426                                         goto free_old_hdr;
 427                                 }
 428                         }
 429                 } else
 430                         req_pack_id = old_hdr->pack_id;
 431         }
 432         srp = sg_get_rq_mark(sfp, req_pack_id);
 433         if (!srp) {             /* now wait on packet to arrive */
 434                 if (atomic_read(&sdp->detaching)) {
 435                         retval = -ENODEV;
 436                         goto free_old_hdr;
 437                 }
 438                 if (filp->f_flags & O_NONBLOCK) {
 439                         retval = -EAGAIN;
 440                         goto free_old_hdr;
 441                 }
 442                 retval = wait_event_interruptible(sfp->read_wait,
 443                         (atomic_read(&sdp->detaching) ||
 444                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 445                 if (atomic_read(&sdp->detaching)) {
 446                         retval = -ENODEV;
 447                         goto free_old_hdr;
 448                 }
 449                 if (retval) {
 450                         /* -ERESTARTSYS as signal hit process */
 451                         goto free_old_hdr;
 452                 }
 453         }
 454         if (srp->header.interface_id != '\0') {
 455                 retval = sg_new_read(sfp, buf, count, srp);
 456                 goto free_old_hdr;
 457         }
 458
 459         hp = &srp->header;
 460         if (old_hdr == NULL) {
 461                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 462                 if (! old_hdr) {
 463                         retval = -ENOMEM;
 464                         goto free_old_hdr;
 465                 }
 466         }
 467         memset(old_hdr, 0, SZ_SG_HEADER);
 468         old_hdr->reply_len = (int) hp->timeout;
 469         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 470         old_hdr->pack_id = hp->pack_id;
 471         old_hdr->twelve_byte =
 472             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 473         old_hdr->target_status = hp->masked_status;
 474         old_hdr->host_status = hp->host_status;
 475         old_hdr->driver_status = hp->driver_status;
 476         if ((CHECK_CONDITION & hp->masked_status) ||
 477             (DRIVER_SENSE & hp->driver_status))
 478                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 479                        sizeof (old_hdr->sense_buffer));
 480         switch (hp->host_status) {
 481         /* This setup of 'result' is for backward compatibility and is best
 482            ignored by the user who should use target, host + driver status */
 483         case DID_OK:
 484         case DID_PASSTHROUGH:
 485         case DID_SOFT_ERROR:
 486                 old_hdr->result = 0;
 487                 break;
 488         case DID_NO_CONNECT:
 489         case DID_BUS_BUSY:
 490         case DID_TIME_OUT:
 491                 old_hdr->result = EBUSY;
 492                 break;
 493         case DID_BAD_TARGET:
 494         case DID_ABORT:
 495         case DID_PARITY:
 496         case DID_RESET:
 497         case DID_BAD_INTR:
 498                 old_hdr->result = EIO;
 499                 break;
 500         case DID_ERROR:
 501                 old_hdr->result = (srp->sense_b[0] == 0 &&
 502                                   hp->masked_status == GOOD) ? 0 : EIO;
 503                 break;
 504         default:
 505                 old_hdr->result = EIO;
 506                 break;
 507         }
 508
 509         /* Now copy the result back to the user buffer.  */
 510         if (count >= SZ_SG_HEADER) {
 511                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 512                         retval = -EFAULT;
 513                         goto free_old_hdr;
 514                 }
 515                 buf += SZ_SG_HEADER;
 516                 if (count > old_hdr->reply_len)
 517                         count = old_hdr->reply_len;
 518                 if (count > SZ_SG_HEADER) {
 519                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 520                                 retval = -EFAULT;
 521                                 goto free_old_hdr;
 522                         }
 523                 }
 524         } else
 525                 count = (old_hdr->result == 0) ? 0 : -EIO;
 526         sg_finish_rem_req(srp);
 527         sg_remove_request(sfp, srp);
 528         retval = count;
 529 free_old_hdr:
 530         kfree(old_hdr);
 531         return retval;
 532 }
 533
 534 static ssize_t
 535 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 536 {
 537         sg_io_hdr_t *hp = &srp->header;
 538         int err = 0, err2;
 539         int len;
 540
 541         if (count < SZ_SG_IO_HDR) {
 542                 err = -EINVAL;
 543                 goto err_out;
 544         }
 545         hp->sb_len_wr = 0;
 546         if ((hp->mx_sb_len > 0) && hp->sbp) {
 547                 if ((CHECK_CONDITION & hp->masked_status) ||
 548                     (DRIVER_SENSE & hp->driver_status)) {
 549                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 550                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 551                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 552                         len = (len > sb_len) ? sb_len : len;
 553                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 554                                 err = -EFAULT;
 555                                 goto err_out;
 556                         }
 557                         hp->sb_len_wr = len;
 558                 }
 559         }
 560         if (hp->masked_status || hp->host_status || hp->driver_status)
 561                 hp->info |= SG_INFO_CHECK;
 562         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 563                 err = -EFAULT;
 564                 goto err_out;
 565         }
 566 err_out:
 567         err2 = sg_finish_rem_req(srp);
 568         sg_remove_request(sfp, srp);
 569         return err ? : err2 ? : count;
 570 }
 571
 572 static ssize_t
 573 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 574 {
 575         int mxsize, cmd_size, k;
 576         int input_size, blocking;
 577         unsigned char opcode;
 578         Sg_device *sdp;
 579         Sg_fd *sfp;
 580         Sg_request *srp;
 581         struct sg_header old_hdr;
 582         sg_io_hdr_t *hp;
 583         unsigned char cmnd[SG_MAX_CDB_SIZE];
 584
 585         if (unlikely(uaccess_kernel()))
 586                 return -EINVAL;
 587
 588         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 589                 return -ENXIO;
 590         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 591                                       "sg_write: count=%d\n", (int) count));
 592         if (atomic_read(&sdp->detaching))
 593                 return -ENODEV;
 594         if (!((filp->f_flags & O_NONBLOCK) ||
 595               scsi_block_when_processing_errors(sdp->device)))
 596                 return -ENXIO;
 597
 598         if (!access_ok(VERIFY_READ, buf, count))
 599                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 600         if (count < SZ_SG_HEADER)
 601                 return -EIO;
 602         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 603                 return -EFAULT;
 604         blocking = !(filp->f_flags & O_NONBLOCK);
 605         if (old_hdr.reply_len < 0)
 606                 return sg_new_write(sfp, filp, buf, count,
 607                                     blocking, 0, 0, NULL);
 608         if (count < (SZ_SG_HEADER + 6))
 609                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 610
 611         if (!(srp = sg_add_request(sfp))) {
 612                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 613                                               "sg_write: queue full\n"));
 614                 return -EDOM;
 615         }
 616         buf += SZ_SG_HEADER;
 617         __get_user(opcode, buf);
 618         mutex_lock(&sfp->f_mutex);
 619         if (sfp->next_cmd_len > 0) {
 620                 cmd_size = sfp->next_cmd_len;
 621                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 622         } else {
 623                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 624                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 625                         cmd_size = 12;
 626         }
 627         mutex_unlock(&sfp->f_mutex);
 628         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 629                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 630 /* Determine buffer size.  */
 631         input_size = count - cmd_size;
 632         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 633         mxsize -= SZ_SG_HEADER;
 634         input_size -= SZ_SG_HEADER;
 635         if (input_size < 0) {
 636                 sg_remove_request(sfp, srp);
 637                 return -EIO;    /* User did not pass enough bytes for this command. */
 638         }
 639         hp = &srp->header;
 640         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 641         hp->cmd_len = (unsigned char) cmd_size;
 642         hp->iovec_count = 0;
 643         hp->mx_sb_len = 0;
 644         if (input_size > 0)
 645                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 646                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 647         else
 648                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 649         hp->dxfer_len = mxsize;
 650         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 651             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 652                 hp->dxferp = (char __user *)buf + cmd_size;
 653         else
 654                 hp->dxferp = NULL;
 655         hp->sbp = NULL;
 656         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 657         hp->flags = input_size; /* structure abuse ... */
 658         hp->pack_id = old_hdr.pack_id;
 659         hp->usr_ptr = NULL;
 660         if (__copy_from_user(cmnd, buf, cmd_size))
 661                 return -EFAULT;
 662         /*
 663          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 664          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 665          * is a non-zero input_size, so emit a warning.
 666          */
 667         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 668                 printk_ratelimited(KERN_WARNING
 669                                    "sg_write: data in/out %d/%d bytes "
 670                                    "for SCSI command 0x%x-- guessing "
 671                                    "data in;\n   program %s not setting "
 672                                    "count and/or reply_len properly\n",
 673                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 674                                    input_size, (unsigned int) cmnd[0],
 675                                    current->comm);
 676         }
 677         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 678         return (k < 0) ? k : count;
 679 }
 680
 681 static ssize_t
 682 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 683                  size_t count, int blocking, int read_only, int sg_io_owned,
 684                  Sg_request **o_srp)
 685 {
 686         int k;
 687         Sg_request *srp;
 688         sg_io_hdr_t *hp;
 689         unsigned char cmnd[SG_MAX_CDB_SIZE];
 690         int timeout;
 691         unsigned long ul_timeout;
 692
 693         if (count < SZ_SG_IO_HDR)
 694                 return -EINVAL;
 695         if (!access_ok(VERIFY_READ, buf, count))
 696                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 697
 698         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 699         if (!(srp = sg_add_request(sfp))) {
 700                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 701                                               "sg_new_write: queue full\n"));
 702                 return -EDOM;
 703         }
 704         srp->sg_io_owned = sg_io_owned;
 705         hp = &srp->header;
 706         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 707                 sg_remove_request(sfp, srp);
 708                 return -EFAULT;
 709         }
 710         if (hp->interface_id != 'S') {
 711                 sg_remove_request(sfp, srp);
 712                 return -ENOSYS;
 713         }
 714         if (hp->flags & SG_FLAG_MMAP_IO) {
 715                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 716                         sg_remove_request(sfp, srp);
 717                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 718                 }
 719                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 720                         sg_remove_request(sfp, srp);
 721                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 722                 }
 723                 if (sfp->res_in_use) {
 724                         sg_remove_request(sfp, srp);
 725                         return -EBUSY;  /* reserve buffer already being used */
 726                 }
 727         }
 728         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 729         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 730         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 731                 sg_remove_request(sfp, srp);
 732                 return -EMSGSIZE;
 733         }
 734         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 735                 sg_remove_request(sfp, srp);
 736                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 737         }
 738         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 739                 sg_remove_request(sfp, srp);
 740                 return -EFAULT;
 741         }
 742         if (read_only && sg_allow_access(file, cmnd)) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EPERM;
 745         }
 746         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 747         if (k < 0)
 748                 return k;
 749         if (o_srp)
 750                 *o_srp = srp;
 751         return count;
 752 }
 753
 754 static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
 755 {
 756         switch (hp->dxfer_direction) {
 757         case SG_DXFER_NONE:
 758                 if (hp->dxferp || hp->dxfer_len > 0)
 759                         return false;
 760                 return true;
 761         case SG_DXFER_FROM_DEV:
 762                 /*
 763                  * for SG_DXFER_FROM_DEV we always set dxfer_len to > 0. dxferp
 764                  * can either be NULL or != NULL so there's no point in checking
 765                  * it either. So just return true.
 766                  */
 767                 return true;
 768         case SG_DXFER_TO_DEV:
 769         case SG_DXFER_TO_FROM_DEV:
 770                 if (!hp->dxferp || hp->dxfer_len == 0)
 771                         return false;
 772                 return true;
 773         case SG_DXFER_UNKNOWN:
 774                 if ((!hp->dxferp && hp->dxfer_len) ||
 775                     (hp->dxferp && hp->dxfer_len == 0))
 776                         return false;
 777                 return true;
 778         default:
 779                 return false;
 780         }
 781 }
 782
 783 static int
 784 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 785                 unsigned char *cmnd, int timeout, int blocking)
 786 {
 787         int k, at_head;
 788         Sg_device *sdp = sfp->parentdp;
 789         sg_io_hdr_t *hp = &srp->header;
 790
 791         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 792         hp->status = 0;
 793         hp->masked_status = 0;
 794         hp->msg_status = 0;
 795         hp->info = 0;
 796         hp->host_status = 0;
 797         hp->driver_status = 0;
 798         hp->resid = 0;
 799         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 800                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 801                         (int) cmnd[0], (int) hp->cmd_len));
 802
 803         if (!sg_is_valid_dxfer(hp))
 804                 return -EINVAL;
 805
 806         k = sg_start_req(srp, cmnd);
 807         if (k) {
 808                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 809                         "sg_common_write: start_req err=%d\n", k));
 810                 sg_finish_rem_req(srp);
 811                 sg_remove_request(sfp, srp);
 812                 return k;       /* probably out of space --> ENOMEM */
 813         }
 814         if (atomic_read(&sdp->detaching)) {
 815                 if (srp->bio) {
 816                         scsi_req_free_cmd(scsi_req(srp->rq));
 817                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 818                         srp->rq = NULL;
 819                 }
 820
 821                 sg_finish_rem_req(srp);
 822                 sg_remove_request(sfp, srp);
 823                 return -ENODEV;
 824         }
 825
 826         hp->duration = jiffies_to_msecs(jiffies);
 827         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 828             (SG_FLAG_Q_AT_TAIL & hp->flags))
 829                 at_head = 0;
 830         else
 831                 at_head = 1;
 832
 833         srp->rq->timeout = timeout;
 834         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 835         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 836                               srp->rq, at_head, sg_rq_end_io);
 837         return 0;
 838 }
 839
 840 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 841 {
 842         unsigned long flags;
 843         int ret;
 844
 845         read_lock_irqsave(&sfp->rq_list_lock, flags);
 846         ret = srp->done;
 847         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 848         return ret;
 849 }
 850
 851 static int max_sectors_bytes(struct request_queue *q)
 852 {
 853         unsigned int max_sectors = queue_max_sectors(q);
 854
 855         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 856
 857         return max_sectors << 9;
 858 }
 859
 860 static long
 861 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 862 {
 863         void __user *p = (void __user *)arg;
 864         int __user *ip = p;
 865         int result, val, read_only;
 866         Sg_device *sdp;
 867         Sg_fd *sfp;
 868         Sg_request *srp;
 869         unsigned long iflags;
 870
 871         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 872                 return -ENXIO;
 873
 874         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 875                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 876         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 877
 878         switch (cmd_in) {
 879         case SG_IO:
 880                 if (atomic_read(&sdp->detaching))
 881                         return -ENODEV;
 882                 if (!scsi_block_when_processing_errors(sdp->device))
 883                         return -ENXIO;
 884                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 885                         return -EFAULT;
 886                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 887                                  1, read_only, 1, &srp);
 888                 if (result < 0)
 889                         return result;
 890                 result = wait_event_interruptible(sfp->read_wait,
 891                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 892                 if (atomic_read(&sdp->detaching))
 893                         return -ENODEV;
 894                 write_lock_irq(&sfp->rq_list_lock);
 895                 if (srp->done) {
 896                         srp->done = 2;
 897                         write_unlock_irq(&sfp->rq_list_lock);
 898                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 899                         return (result < 0) ? result : 0;
 900                 }
 901                 srp->orphan = 1;
 902                 write_unlock_irq(&sfp->rq_list_lock);
 903                 return result;  /* -ERESTARTSYS because signal hit process */
 904         case SG_SET_TIMEOUT:
 905                 result = get_user(val, ip);
 906                 if (result)
 907                         return result;
 908                 if (val < 0)
 909                         return -EIO;
 910                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 911                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 912                                     INT_MAX);
 913                 sfp->timeout_user = val;
 914                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 915
 916                 return 0;
 917         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 918                                 /* strange ..., for backward compatibility */
 919                 return sfp->timeout_user;
 920         case SG_SET_FORCE_LOW_DMA:
 921                 /*
 922                  * N.B. This ioctl never worked properly, but failed to
 923                  * return an error value. So returning '0' to keep compability
 924                  * with legacy applications.
 925                  */
 926                 return 0;
 927         case SG_GET_LOW_DMA:
 928                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 929         case SG_GET_SCSI_ID:
 930                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 931                         return -EFAULT;
 932                 else {
 933                         sg_scsi_id_t __user *sg_idp = p;
 934
 935                         if (atomic_read(&sdp->detaching))
 936                                 return -ENODEV;
 937                         __put_user((int) sdp->device->host->host_no,
 938                                    &sg_idp->host_no);
 939                         __put_user((int) sdp->device->channel,
 940                                    &sg_idp->channel);
 941                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 942                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 943                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 944                         __put_user((short) sdp->device->host->cmd_per_lun,
 945                                    &sg_idp->h_cmd_per_lun);
 946                         __put_user((short) sdp->device->queue_depth,
 947                                    &sg_idp->d_queue_depth);
 948                         __put_user(0, &sg_idp->unused[0]);
 949                         __put_user(0, &sg_idp->unused[1]);
 950                         return 0;
 951                 }
 952         case SG_SET_FORCE_PACK_ID:
 953                 result = get_user(val, ip);
 954                 if (result)
 955                         return result;
 956                 sfp->force_packid = val ? 1 : 0;
 957                 return 0;
 958         case SG_GET_PACK_ID:
 959                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 960                         return -EFAULT;
 961                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 962                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 963                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 964                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 965                                                        iflags);
 966                                 __put_user(srp->header.pack_id, ip);
 967                                 return 0;
 968                         }
 969                 }
 970                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 971                 __put_user(-1, ip);
 972                 return 0;
 973         case SG_GET_NUM_WAITING:
 974                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 975                 val = 0;
 976                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 977                         if ((1 == srp->done) && (!srp->sg_io_owned))
 978                                 ++val;
 979                 }
 980                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 981                 return put_user(val, ip);
 982         case SG_GET_SG_TABLESIZE:
 983                 return put_user(sdp->sg_tablesize, ip);
 984         case SG_SET_RESERVED_SIZE:
 985                 result = get_user(val, ip);
 986                 if (result)
 987                         return result;
 988                 if (val < 0)
 989                         return -EINVAL;
 990                 val = min_t(int, val,
 991                             max_sectors_bytes(sdp->device->request_queue));
 992                 mutex_lock(&sfp->f_mutex);
 993                 if (val != sfp->reserve.bufflen) {
 994                         if (sfp->mmap_called ||
 995                             sfp->res_in_use) {
 996                                 mutex_unlock(&sfp->f_mutex);
 997                                 return -EBUSY;
 998                         }
 999
1000                         sg_remove_scat(sfp, &sfp->reserve);
1001                         sg_build_reserve(sfp, val);
1002                 }
1003                 mutex_unlock(&sfp->f_mutex);
1004                 return 0;
1005         case SG_GET_RESERVED_SIZE:
1006                 val = min_t(int, sfp->reserve.bufflen,
1007                             max_sectors_bytes(sdp->device->request_queue));
1008                 return put_user(val, ip);
1009         case SG_SET_COMMAND_Q:
1010                 result = get_user(val, ip);
1011                 if (result)
1012                         return result;
1013                 sfp->cmd_q = val ? 1 : 0;
1014                 return 0;
1015         case SG_GET_COMMAND_Q:
1016                 return put_user((int) sfp->cmd_q, ip);
1017         case SG_SET_KEEP_ORPHAN:
1018                 result = get_user(val, ip);
1019                 if (result)
1020                         return result;
1021                 sfp->keep_orphan = val;
1022                 return 0;
1023         case SG_GET_KEEP_ORPHAN:
1024                 return put_user((int) sfp->keep_orphan, ip);
1025         case SG_NEXT_CMD_LEN:
1026                 result = get_user(val, ip);
1027                 if (result)
1028                         return result;
1029                 if (val > SG_MAX_CDB_SIZE)
1030                         return -ENOMEM;
1031                 sfp->next_cmd_len = (val > 0) ? val : 0;
1032                 return 0;
1033         case SG_GET_VERSION_NUM:
1034                 return put_user(sg_version_num, ip);
1035         case SG_GET_ACCESS_COUNT:
1036                 /* faked - we don't have a real access count anymore */
1037                 val = (sdp->device ? 1 : 0);
1038                 return put_user(val, ip);
1039         case SG_GET_REQUEST_TABLE:
1040                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1041                         return -EFAULT;
1042                 else {
1043                         sg_req_info_t *rinfo;
1044                         unsigned int ms;
1045
1046                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1047                                                                 GFP_KERNEL);
1048                         if (!rinfo)
1049                                 return -ENOMEM;
1050                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1051                         val = 0;
1052                         list_for_each_entry(srp, &sfp->rq_list, entry) {
1053                                 if (val > SG_MAX_QUEUE)
1054                                         break;
1055                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1056                                 rinfo[val].req_state = srp->done + 1;
1057                                 rinfo[val].problem =
1058                                         srp->header.masked_status &
1059                                         srp->header.host_status &
1060                                         srp->header.driver_status;
1061                                 if (srp->done)
1062                                         rinfo[val].duration =
1063                                                 srp->header.duration;
1064                                 else {
1065                                         ms = jiffies_to_msecs(jiffies);
1066                                         rinfo[val].duration =
1067                                                 (ms > srp->header.duration) ?
1068                                                 (ms - srp->header.duration) : 0;
1069                                 }
1070                                 rinfo[val].orphan = srp->orphan;
1071                                 rinfo[val].sg_io_owned = srp->sg_io_owned;
1072                                 rinfo[val].pack_id = srp->header.pack_id;
1073                                 rinfo[val].usr_ptr = srp->header.usr_ptr;
1074                                 val++;
1075                         }
1076                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1077                         result = __copy_to_user(p, rinfo,
1078                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1079                         result = result ? -EFAULT : 0;
1080                         kfree(rinfo);
1081                         return result;
1082                 }
1083         case SG_EMULATED_HOST:
1084                 if (atomic_read(&sdp->detaching))
1085                         return -ENODEV;
1086                 return put_user(sdp->device->host->hostt->emulated, ip);
1087         case SCSI_IOCTL_SEND_COMMAND:
1088                 if (atomic_read(&sdp->detaching))
1089                         return -ENODEV;
1090                 if (read_only) {
1091                         unsigned char opcode = WRITE_6;
1092                         Scsi_Ioctl_Command __user *siocp = p;
1093
1094                         if (copy_from_user(&opcode, siocp->data, 1))
1095                                 return -EFAULT;
1096                         if (sg_allow_access(filp, &opcode))
1097                                 return -EPERM;
1098                 }
1099                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1100         case SG_SET_DEBUG:
1101                 result = get_user(val, ip);
1102                 if (result)
1103                         return result;
1104                 sdp->sgdebug = (char) val;
1105                 return 0;
1106         case BLKSECTGET:
1107                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1108                                 ip);
1109         case BLKTRACESETUP:
1110                 return blk_trace_setup(sdp->device->request_queue,
1111                                        sdp->disk->disk_name,
1112                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1113                                        NULL,
1114                                        (char *)arg);
1115         case BLKTRACESTART:
1116                 return blk_trace_startstop(sdp->device->request_queue, 1);
1117         case BLKTRACESTOP:
1118                 return blk_trace_startstop(sdp->device->request_queue, 0);
1119         case BLKTRACETEARDOWN:
1120                 return blk_trace_remove(sdp->device->request_queue);
1121         case SCSI_IOCTL_GET_IDLUN:
1122         case SCSI_IOCTL_GET_BUS_NUMBER:
1123         case SCSI_IOCTL_PROBE_HOST:
1124         case SG_GET_TRANSFORM:
1125         case SG_SCSI_RESET:
1126                 if (atomic_read(&sdp->detaching))
1127                         return -ENODEV;
1128                 break;
1129         default:
1130                 if (read_only)
1131                         return -EPERM;  /* don't know so take safe approach */
1132                 break;
1133         }
1134
1135         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1136                         cmd_in, filp->f_flags & O_NDELAY);
1137         if (result)
1138                 return result;
1139         return scsi_ioctl(sdp->device, cmd_in, p);
1140 }
1141
1142 #ifdef CONFIG_COMPAT
1143 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1144 {
1145         Sg_device *sdp;
1146         Sg_fd *sfp;
1147         struct scsi_device *sdev;
1148
1149         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1150                 return -ENXIO;
1151
1152         sdev = sdp->device;
1153         if (sdev->host->hostt->compat_ioctl) {
1154                 int ret;
1155
1156                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1157
1158                 return ret;
1159         }
1160
1161         return -ENOIOCTLCMD;
1162 }
1163 #endif
1164
1165 static unsigned int
1166 sg_poll(struct file *filp, poll_table * wait)
1167 {
1168         unsigned int res = 0;
1169         Sg_device *sdp;
1170         Sg_fd *sfp;
1171         Sg_request *srp;
1172         int count = 0;
1173         unsigned long iflags;
1174
1175         sfp = filp->private_data;
1176         if (!sfp)
1177                 return POLLERR;
1178         sdp = sfp->parentdp;
1179         if (!sdp)
1180                 return POLLERR;
1181         poll_wait(filp, &sfp->read_wait, wait);
1182         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1183         list_for_each_entry(srp, &sfp->rq_list, entry) {
1184                 /* if any read waiting, flag it */
1185                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1186                         res = POLLIN | POLLRDNORM;
1187                 ++count;
1188         }
1189         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1190
1191         if (atomic_read(&sdp->detaching))
1192                 res |= POLLHUP;
1193         else if (!sfp->cmd_q) {
1194                 if (0 == count)
1195                         res |= POLLOUT | POLLWRNORM;
1196         } else if (count < SG_MAX_QUEUE)
1197                 res |= POLLOUT | POLLWRNORM;
1198         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1199                                       "sg_poll: res=0x%x\n", (int) res));
1200         return res;
1201 }
1202
1203 static int
1204 sg_fasync(int fd, struct file *filp, int mode)
1205 {
1206         Sg_device *sdp;
1207         Sg_fd *sfp;
1208
1209         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1210                 return -ENXIO;
1211         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1212                                       "sg_fasync: mode=%d\n", mode));
1213
1214         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1215 }
1216
1217 static int
1218 sg_vma_fault(struct vm_fault *vmf)
1219 {
1220         struct vm_area_struct *vma = vmf->vma;
1221         Sg_fd *sfp;
1222         unsigned long offset, len, sa;
1223         Sg_scatter_hold *rsv_schp;
1224         int k, length;
1225
1226         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1227                 return VM_FAULT_SIGBUS;
1228         rsv_schp = &sfp->reserve;
1229         offset = vmf->pgoff << PAGE_SHIFT;
1230         if (offset >= rsv_schp->bufflen)
1231                 return VM_FAULT_SIGBUS;
1232         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1233                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1234                                       offset, rsv_schp->k_use_sg));
1235         sa = vma->vm_start;
1236         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1237         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1238                 len = vma->vm_end - sa;
1239                 len = (len < length) ? len : length;
1240                 if (offset < len) {
1241                         struct page *page = nth_page(rsv_schp->pages[k],
1242                                                      offset >> PAGE_SHIFT);
1243                         get_page(page); /* increment page count */
1244                         vmf->page = page;
1245                         return 0; /* success */
1246                 }
1247                 sa += len;
1248                 offset -= len;
1249         }
1250
1251         return VM_FAULT_SIGBUS;
1252 }
1253
1254 static const struct vm_operations_struct sg_mmap_vm_ops = {
1255         .fault = sg_vma_fault,
1256 };
1257
1258 static int
1259 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1260 {
1261         Sg_fd *sfp;
1262         unsigned long req_sz, len, sa;
1263         Sg_scatter_hold *rsv_schp;
1264         int k, length;
1265
1266         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1267                 return -ENXIO;
1268         req_sz = vma->vm_end - vma->vm_start;
1269         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1270                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1271                                       (void *) vma->vm_start, (int) req_sz));
1272         if (vma->vm_pgoff)
1273                 return -EINVAL; /* want no offset */
1274         rsv_schp = &sfp->reserve;
1275         if (req_sz > rsv_schp->bufflen)
1276                 return -ENOMEM; /* cannot map more than reserved buffer */
1277
1278         sa = vma->vm_start;
1279         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1280         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1281                 len = vma->vm_end - sa;
1282                 len = (len < length) ? len : length;
1283                 sa += len;
1284         }
1285
1286         sfp->mmap_called = 1;
1287         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1288         vma->vm_private_data = sfp;
1289         vma->vm_ops = &sg_mmap_vm_ops;
1290         return 0;
1291 }
1292
1293 static void
1294 sg_rq_end_io_usercontext(struct work_struct *work)
1295 {
1296         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1297         struct sg_fd *sfp = srp->parentfp;
1298
1299         sg_finish_rem_req(srp);
1300         sg_remove_request(sfp, srp);
1301         kref_put(&sfp->f_ref, sg_remove_sfp);
1302 }
1303
1304 /*
1305  * This function is a "bottom half" handler that is called by the mid
1306  * level when a command is completed (or has failed).
1307  */
1308 static void
1309 sg_rq_end_io(struct request *rq, blk_status_t status)
1310 {
1311         struct sg_request *srp = rq->end_io_data;
1312         struct scsi_request *req = scsi_req(rq);
1313         Sg_device *sdp;
1314         Sg_fd *sfp;
1315         unsigned long iflags;
1316         unsigned int ms;
1317         char *sense;
1318         int result, resid, done = 1;
1319
1320         if (WARN_ON(srp->done != 0))
1321                 return;
1322
1323         sfp = srp->parentfp;
1324         if (WARN_ON(sfp == NULL))
1325                 return;
1326
1327         sdp = sfp->parentdp;
1328         if (unlikely(atomic_read(&sdp->detaching)))
1329                 pr_info("%s: device detaching\n", __func__);
1330
1331         sense = req->sense;
1332         result = req->result;
1333         resid = req->resid_len;
1334
1335         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1336                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1337                                       srp->header.pack_id, result));
1338         srp->header.resid = resid;
1339         ms = jiffies_to_msecs(jiffies);
1340         srp->header.duration = (ms > srp->header.duration) ?
1341                                 (ms - srp->header.duration) : 0;
1342         if (0 != result) {
1343                 struct scsi_sense_hdr sshdr;
1344
1345                 srp->header.status = 0xff & result;
1346                 srp->header.masked_status = status_byte(result);
1347                 srp->header.msg_status = msg_byte(result);
1348                 srp->header.host_status = host_byte(result);
1349                 srp->header.driver_status = driver_byte(result);
1350                 if ((sdp->sgdebug > 0) &&
1351                     ((CHECK_CONDITION == srp->header.masked_status) ||
1352                      (COMMAND_TERMINATED == srp->header.masked_status)))
1353                         __scsi_print_sense(sdp->device, __func__, sense,
1354                                            SCSI_SENSE_BUFFERSIZE);
1355
1356                 /* Following if statement is a patch supplied by Eric Youngdale */
1357                 if (driver_byte(result) != 0
1358                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1359                     && !scsi_sense_is_deferred(&sshdr)
1360                     && sshdr.sense_key == UNIT_ATTENTION
1361                     && sdp->device->removable) {
1362                         /* Detected possible disc change. Set the bit - this */
1363                         /* may be used if there are filesystems using this device */
1364                         sdp->device->changed = 1;
1365                 }
1366         }
1367
1368         if (req->sense_len)
1369                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1370
1371         /* Rely on write phase to clean out srp status values, so no "else" */
1372
1373         /*
1374          * Free the request as soon as it is complete so that its resources
1375          * can be reused without waiting for userspace to read() the
1376          * result.  But keep the associated bio (if any) around until
1377          * blk_rq_unmap_user() can be called from user context.
1378          */
1379         srp->rq = NULL;
1380         scsi_req_free_cmd(scsi_req(rq));
1381         __blk_put_request(rq->q, rq);
1382
1383         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1384         if (unlikely(srp->orphan)) {
1385                 if (sfp->keep_orphan)
1386                         srp->sg_io_owned = 0;
1387                 else
1388                         done = 0;
1389         }
1390         srp->done = done;
1391         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1392
1393         if (likely(done)) {
1394                 /* Now wake up any sg_read() that is waiting for this
1395                  * packet.
1396                  */
1397                 wake_up_interruptible(&sfp->read_wait);
1398                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1399                 kref_put(&sfp->f_ref, sg_remove_sfp);
1400         } else {
1401                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1402                 schedule_work(&srp->ew.work);
1403         }
1404 }
1405
1406 static const struct file_operations sg_fops = {
1407         .owner = THIS_MODULE,
1408         .read = sg_read,
1409         .write = sg_write,
1410         .poll = sg_poll,
1411         .unlocked_ioctl = sg_ioctl,
1412 #ifdef CONFIG_COMPAT
1413         .compat_ioctl = sg_compat_ioctl,
1414 #endif
1415         .open = sg_open,
1416         .mmap = sg_mmap,
1417         .release = sg_release,
1418         .fasync = sg_fasync,
1419         .llseek = no_llseek,
1420 };
1421
1422 static struct class *sg_sysfs_class;
1423
1424 static int sg_sysfs_valid = 0;
1425
1426 static Sg_device *
1427 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1428 {
1429         struct request_queue *q = scsidp->request_queue;
1430         Sg_device *sdp;
1431         unsigned long iflags;
1432         int error;
1433         u32 k;
1434
1435         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1436         if (!sdp) {
1437                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1438                             "failure\n", __func__);
1439                 return ERR_PTR(-ENOMEM);
1440         }
1441
1442         idr_preload(GFP_KERNEL);
1443         write_lock_irqsave(&sg_index_lock, iflags);
1444
1445         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1446         if (error < 0) {
1447                 if (error == -ENOSPC) {
1448                         sdev_printk(KERN_WARNING, scsidp,
1449                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1450                                     scsidp->type, SG_MAX_DEVS - 1);
1451                         error = -ENODEV;
1452                 } else {
1453                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1454                                     "allocation Sg_device failure: %d\n",
1455                                     __func__, error);
1456                 }
1457                 goto out_unlock;
1458         }
1459         k = error;
1460
1461         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1462                                         "sg_alloc: dev=%d \n", k));
1463         sprintf(disk->disk_name, "sg%d", k);
1464         disk->first_minor = k;
1465         sdp->disk = disk;
1466         sdp->device = scsidp;
1467         mutex_init(&sdp->open_rel_lock);
1468         INIT_LIST_HEAD(&sdp->sfds);
1469         init_waitqueue_head(&sdp->open_wait);
1470         atomic_set(&sdp->detaching, 0);
1471         rwlock_init(&sdp->sfd_lock);
1472         sdp->sg_tablesize = queue_max_segments(q);
1473         sdp->index = k;
1474         kref_init(&sdp->d_ref);
1475         error = 0;
1476
1477 out_unlock:
1478         write_unlock_irqrestore(&sg_index_lock, iflags);
1479         idr_preload_end();
1480
1481         if (error) {
1482                 kfree(sdp);
1483                 return ERR_PTR(error);
1484         }
1485         return sdp;
1486 }
1487
1488 static int
1489 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1490 {
1491         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1492         struct gendisk *disk;
1493         Sg_device *sdp = NULL;
1494         struct cdev * cdev = NULL;
1495         int error;
1496         unsigned long iflags;
1497
1498         disk = alloc_disk(1);
1499         if (!disk) {
1500                 pr_warn("%s: alloc_disk failed\n", __func__);
1501                 return -ENOMEM;
1502         }
1503         disk->major = SCSI_GENERIC_MAJOR;
1504
1505         error = -ENOMEM;
1506         cdev = cdev_alloc();
1507         if (!cdev) {
1508                 pr_warn("%s: cdev_alloc failed\n", __func__);
1509                 goto out;
1510         }
1511         cdev->owner = THIS_MODULE;
1512         cdev->ops = &sg_fops;
1513
1514         sdp = sg_alloc(disk, scsidp);
1515         if (IS_ERR(sdp)) {
1516                 pr_warn("%s: sg_alloc failed\n", __func__);
1517                 error = PTR_ERR(sdp);
1518                 goto out;
1519         }
1520
1521         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1522         if (error)
1523                 goto cdev_add_err;
1524
1525         sdp->cdev = cdev;
1526         if (sg_sysfs_valid) {
1527                 struct device *sg_class_member;
1528
1529                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1530                                                 MKDEV(SCSI_GENERIC_MAJOR,
1531                                                       sdp->index),
1532                                                 sdp, "%s", disk->disk_name);
1533                 if (IS_ERR(sg_class_member)) {
1534                         pr_err("%s: device_create failed\n", __func__);
1535                         error = PTR_ERR(sg_class_member);
1536                         goto cdev_add_err;
1537                 }
1538                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1539                                           &sg_class_member->kobj, "generic");
1540                 if (error)
1541                         pr_err("%s: unable to make symlink 'generic' back "
1542                                "to sg%d\n", __func__, sdp->index);
1543         } else
1544                 pr_warn("%s: sg_sys Invalid\n", __func__);
1545
1546         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1547                     "type %d\n", sdp->index, scsidp->type);
1548
1549         dev_set_drvdata(cl_dev, sdp);
1550
1551         return 0;
1552
1553 cdev_add_err:
1554         write_lock_irqsave(&sg_index_lock, iflags);
1555         idr_remove(&sg_index_idr, sdp->index);
1556         write_unlock_irqrestore(&sg_index_lock, iflags);
1557         kfree(sdp);
1558
1559 out:
1560         put_disk(disk);
1561         if (cdev)
1562                 cdev_del(cdev);
1563         return error;
1564 }
1565
1566 static void
1567 sg_device_destroy(struct kref *kref)
1568 {
1569         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1570         unsigned long flags;
1571
1572         /* CAUTION!  Note that the device can still be found via idr_find()
1573          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1574          * any other cleanup.
1575          */
1576
1577         write_lock_irqsave(&sg_index_lock, flags);
1578         idr_remove(&sg_index_idr, sdp->index);
1579         write_unlock_irqrestore(&sg_index_lock, flags);
1580
1581         SCSI_LOG_TIMEOUT(3,
1582                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1583
1584         put_disk(sdp->disk);
1585         kfree(sdp);
1586 }
1587
1588 static void
1589 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1590 {
1591         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1592         Sg_device *sdp = dev_get_drvdata(cl_dev);
1593         unsigned long iflags;
1594         Sg_fd *sfp;
1595         int val;
1596
1597         if (!sdp)
1598                 return;
1599         /* want sdp->detaching non-zero as soon as possible */
1600         val = atomic_inc_return(&sdp->detaching);
1601         if (val > 1)
1602                 return; /* only want to do following once per device */
1603
1604         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1605                                       "%s\n", __func__));
1606
1607         read_lock_irqsave(&sdp->sfd_lock, iflags);
1608         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1609                 wake_up_interruptible_all(&sfp->read_wait);
1610                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1611         }
1612         wake_up_interruptible_all(&sdp->open_wait);
1613         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1614
1615         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1616         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1617         cdev_del(sdp->cdev);
1618         sdp->cdev = NULL;
1619
1620         kref_put(&sdp->d_ref, sg_device_destroy);
1621 }
1622
1623 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1624 module_param_named(def_reserved_size, def_reserved_size, int,
1625                    S_IRUGO | S_IWUSR);
1626 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1627
1628 MODULE_AUTHOR("Douglas Gilbert");
1629 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1630 MODULE_LICENSE("GPL");
1631 MODULE_VERSION(SG_VERSION_STR);
1632 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1633
1634 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1635                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1636 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1637 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1638
1639 static int __init
1640 init_sg(void)
1641 {
1642         int rc;
1643
1644         if (scatter_elem_sz < PAGE_SIZE) {
1645                 scatter_elem_sz = PAGE_SIZE;
1646                 scatter_elem_sz_prev = scatter_elem_sz;
1647         }
1648         if (def_reserved_size >= 0)
1649                 sg_big_buff = def_reserved_size;
1650         else
1651                 def_reserved_size = sg_big_buff;
1652
1653         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1654                                     SG_MAX_DEVS, "sg");
1655         if (rc)
1656                 return rc;
1657         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1658         if ( IS_ERR(sg_sysfs_class) ) {
1659                 rc = PTR_ERR(sg_sysfs_class);
1660                 goto err_out;
1661         }
1662         sg_sysfs_valid = 1;
1663         rc = scsi_register_interface(&sg_interface);
1664         if (0 == rc) {
1665 #ifdef CONFIG_SCSI_PROC_FS
1666                 sg_proc_init();
1667 #endif                          /* CONFIG_SCSI_PROC_FS */
1668                 return 0;
1669         }
1670         class_destroy(sg_sysfs_class);
1671 err_out:
1672         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1673         return rc;
1674 }
1675
1676 static void __exit
1677 exit_sg(void)
1678 {
1679 #ifdef CONFIG_SCSI_PROC_FS
1680         sg_proc_cleanup();
1681 #endif                          /* CONFIG_SCSI_PROC_FS */
1682         scsi_unregister_interface(&sg_interface);
1683         class_destroy(sg_sysfs_class);
1684         sg_sysfs_valid = 0;
1685         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1686                                  SG_MAX_DEVS);
1687         idr_destroy(&sg_index_idr);
1688 }
1689
1690 static int
1691 sg_start_req(Sg_request *srp, unsigned char *cmd)
1692 {
1693         int res;
1694         struct request *rq;
1695         struct scsi_request *req;
1696         Sg_fd *sfp = srp->parentfp;
1697         sg_io_hdr_t *hp = &srp->header;
1698         int dxfer_len = (int) hp->dxfer_len;
1699         int dxfer_dir = hp->dxfer_direction;
1700         unsigned int iov_count = hp->iovec_count;
1701         Sg_scatter_hold *req_schp = &srp->data;
1702         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1703         struct request_queue *q = sfp->parentdp->device->request_queue;
1704         struct rq_map_data *md, map_data;
1705         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1706         unsigned char *long_cmdp = NULL;
1707
1708         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1709                                       "sg_start_req: dxfer_len=%d\n",
1710                                       dxfer_len));
1711
1712         if (hp->cmd_len > BLK_MAX_CDB) {
1713                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1714                 if (!long_cmdp)
1715                         return -ENOMEM;
1716         }
1717
1718         /*
1719          * NOTE
1720          *
1721          * With scsi-mq enabled, there are a fixed number of preallocated
1722          * requests equal in number to shost->can_queue.  If all of the
1723          * preallocated requests are already in use, then using GFP_ATOMIC with
1724          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1725          * will cause blk_get_request() to sleep until an active command
1726          * completes, freeing up a request.  Neither option is ideal, but
1727          * GFP_KERNEL is the better choice to prevent userspace from getting an
1728          * unexpected EWOULDBLOCK.
1729          *
1730          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1731          * does not sleep except under memory pressure.
1732          */
1733         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1734                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1735         if (IS_ERR(rq)) {
1736                 kfree(long_cmdp);
1737                 return PTR_ERR(rq);
1738         }
1739         req = scsi_req(rq);
1740
1741         if (hp->cmd_len > BLK_MAX_CDB)
1742                 req->cmd = long_cmdp;
1743         memcpy(req->cmd, cmd, hp->cmd_len);
1744         req->cmd_len = hp->cmd_len;
1745
1746         srp->rq = rq;
1747         rq->end_io_data = srp;
1748         req->retries = SG_DEFAULT_RETRIES;
1749
1750         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1751                 return 0;
1752
1753         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1754             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1755             !sfp->parentdp->device->host->unchecked_isa_dma &&
1756             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1757                 md = NULL;
1758         else
1759                 md = &map_data;
1760
1761         if (md) {
1762                 mutex_lock(&sfp->f_mutex);
1763                 if (dxfer_len <= rsv_schp->bufflen &&
1764                     !sfp->res_in_use) {
1765                         sfp->res_in_use = 1;
1766                         sg_link_reserve(sfp, srp, dxfer_len);
1767                 } else if ((hp->flags & SG_FLAG_MMAP_IO) && sfp->res_in_use) {
1768                         mutex_unlock(&sfp->f_mutex);
1769                         return -EBUSY;
1770                 } else {
1771                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1772                         if (res) {
1773                                 mutex_unlock(&sfp->f_mutex);
1774                                 return res;
1775                         }
1776                 }
1777                 mutex_unlock(&sfp->f_mutex);
1778
1779                 md->pages = req_schp->pages;
1780                 md->page_order = req_schp->page_order;
1781                 md->nr_entries = req_schp->k_use_sg;
1782                 md->offset = 0;
1783                 md->null_mapped = hp->dxferp ? 0 : 1;
1784                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1785                         md->from_user = 1;
1786                 else
1787                         md->from_user = 0;
1788         }
1789
1790         if (iov_count) {
1791                 struct iovec *iov = NULL;
1792                 struct iov_iter i;
1793
1794                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1795                 if (res < 0)
1796                         return res;
1797
1798                 iov_iter_truncate(&i, hp->dxfer_len);
1799                 if (!iov_iter_count(&i)) {
1800                         kfree(iov);
1801                         return -EINVAL;
1802                 }
1803
1804                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1805                 kfree(iov);
1806         } else
1807                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1808                                       hp->dxfer_len, GFP_ATOMIC);
1809
1810         if (!res) {
1811                 srp->bio = rq->bio;
1812
1813                 if (!md) {
1814                         req_schp->dio_in_use = 1;
1815                         hp->info |= SG_INFO_DIRECT_IO;
1816                 }
1817         }
1818         return res;
1819 }
1820
1821 static int
1822 sg_finish_rem_req(Sg_request *srp)
1823 {
1824         int ret = 0;
1825
1826         Sg_fd *sfp = srp->parentfp;
1827         Sg_scatter_hold *req_schp = &srp->data;
1828
1829         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1830                                       "sg_finish_rem_req: res_used=%d\n",
1831                                       (int) srp->res_used));
1832         if (srp->bio)
1833                 ret = blk_rq_unmap_user(srp->bio);
1834
1835         if (srp->rq) {
1836                 scsi_req_free_cmd(scsi_req(srp->rq));
1837                 blk_put_request(srp->rq);
1838         }
1839
1840         if (srp->res_used)
1841                 sg_unlink_reserve(sfp, srp);
1842         else
1843                 sg_remove_scat(sfp, req_schp);
1844
1845         return ret;
1846 }
1847
1848 static int
1849 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1850 {
1851         int sg_bufflen = tablesize * sizeof(struct page *);
1852         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1853
1854         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1855         if (!schp->pages)
1856                 return -ENOMEM;
1857         schp->sglist_len = sg_bufflen;
1858         return tablesize;       /* number of scat_gath elements allocated */
1859 }
1860
1861 static int
1862 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1863 {
1864         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1865         int sg_tablesize = sfp->parentdp->sg_tablesize;
1866         int blk_size = buff_size, order;
1867         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1868         struct sg_device *sdp = sfp->parentdp;
1869
1870         if (blk_size < 0)
1871                 return -EFAULT;
1872         if (0 == blk_size)
1873                 ++blk_size;     /* don't know why */
1874         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1875         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1876         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1877                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1878                 buff_size, blk_size));
1879
1880         /* N.B. ret_sz carried into this block ... */
1881         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1882         if (mx_sc_elems < 0)
1883                 return mx_sc_elems;     /* most likely -ENOMEM */
1884
1885         num = scatter_elem_sz;
1886         if (unlikely(num != scatter_elem_sz_prev)) {
1887                 if (num < PAGE_SIZE) {
1888                         scatter_elem_sz = PAGE_SIZE;
1889                         scatter_elem_sz_prev = PAGE_SIZE;
1890                 } else
1891                         scatter_elem_sz_prev = num;
1892         }
1893
1894         if (sdp->device->host->unchecked_isa_dma)
1895                 gfp_mask |= GFP_DMA;
1896
1897         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1898                 gfp_mask |= __GFP_ZERO;
1899
1900         order = get_order(num);
1901 retry:
1902         ret_sz = 1 << (PAGE_SHIFT + order);
1903
1904         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1905              k++, rem_sz -= ret_sz) {
1906
1907                 num = (rem_sz > scatter_elem_sz_prev) ?
1908                         scatter_elem_sz_prev : rem_sz;
1909
1910                 schp->pages[k] = alloc_pages(gfp_mask, order);
1911                 if (!schp->pages[k])
1912                         goto out;
1913
1914                 if (num == scatter_elem_sz_prev) {
1915                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1916                                 scatter_elem_sz = ret_sz;
1917                                 scatter_elem_sz_prev = ret_sz;
1918                         }
1919                 }
1920
1921                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1922                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1923                                  k, num, ret_sz));
1924         }               /* end of for loop */
1925
1926         schp->page_order = order;
1927         schp->k_use_sg = k;
1928         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1929                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1930                          k, rem_sz));
1931
1932         schp->bufflen = blk_size;
1933         if (rem_sz > 0) /* must have failed */
1934                 return -ENOMEM;
1935         return 0;
1936 out:
1937         for (i = 0; i < k; i++)
1938                 __free_pages(schp->pages[i], order);
1939
1940         if (--order >= 0)
1941                 goto retry;
1942
1943         return -ENOMEM;
1944 }
1945
1946 static void
1947 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1948 {
1949         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1950                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1951         if (schp->pages && schp->sglist_len > 0) {
1952                 if (!schp->dio_in_use) {
1953                         int k;
1954
1955                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1956                                 SCSI_LOG_TIMEOUT(5,
1957                                         sg_printk(KERN_INFO, sfp->parentdp,
1958                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1959                                         k, schp->pages[k]));
1960                                 __free_pages(schp->pages[k], schp->page_order);
1961                         }
1962
1963                         kfree(schp->pages);
1964                 }
1965         }
1966         memset(schp, 0, sizeof (*schp));
1967 }
1968
1969 static int
1970 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1971 {
1972         Sg_scatter_hold *schp = &srp->data;
1973         int k, num;
1974
1975         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1976                          "sg_read_oxfer: num_read_xfer=%d\n",
1977                          num_read_xfer));
1978         if ((!outp) || (num_read_xfer <= 0))
1979                 return 0;
1980
1981         num = 1 << (PAGE_SHIFT + schp->page_order);
1982         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1983                 if (num > num_read_xfer) {
1984                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1985                                            num_read_xfer))
1986                                 return -EFAULT;
1987                         break;
1988                 } else {
1989                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1990                                            num))
1991                                 return -EFAULT;
1992                         num_read_xfer -= num;
1993                         if (num_read_xfer <= 0)
1994                                 break;
1995                         outp += num;
1996                 }
1997         }
1998
1999         return 0;
2000 }
2001
2002 static void
2003 sg_build_reserve(Sg_fd * sfp, int req_size)
2004 {
2005         Sg_scatter_hold *schp = &sfp->reserve;
2006
2007         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2008                          "sg_build_reserve: req_size=%d\n", req_size));
2009         do {
2010                 if (req_size < PAGE_SIZE)
2011                         req_size = PAGE_SIZE;
2012                 if (0 == sg_build_indirect(schp, sfp, req_size))
2013                         return;
2014                 else
2015                         sg_remove_scat(sfp, schp);
2016                 req_size >>= 1; /* divide by 2 */
2017         } while (req_size > (PAGE_SIZE / 2));
2018 }
2019
2020 static void
2021 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2022 {
2023         Sg_scatter_hold *req_schp = &srp->data;
2024         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2025         int k, num, rem;
2026
2027         srp->res_used = 1;
2028         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2029                          "sg_link_reserve: size=%d\n", size));
2030         rem = size;
2031
2032         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2033         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2034                 if (rem <= num) {
2035                         req_schp->k_use_sg = k + 1;
2036                         req_schp->sglist_len = rsv_schp->sglist_len;
2037                         req_schp->pages = rsv_schp->pages;
2038
2039                         req_schp->bufflen = size;
2040                         req_schp->page_order = rsv_schp->page_order;
2041                         break;
2042                 } else
2043                         rem -= num;
2044         }
2045
2046         if (k >= rsv_schp->k_use_sg)
2047                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2048                                  "sg_link_reserve: BAD size\n"));
2049 }
2050
2051 static void
2052 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2053 {
2054         Sg_scatter_hold *req_schp = &srp->data;
2055
2056         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2057                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2058                                       (int) req_schp->k_use_sg));
2059         req_schp->k_use_sg = 0;
2060         req_schp->bufflen = 0;
2061         req_schp->pages = NULL;
2062         req_schp->page_order = 0;
2063         req_schp->sglist_len = 0;
2064         srp->res_used = 0;
2065         /* Called without mutex lock to avoid deadlock */
2066         sfp->res_in_use = 0;
2067 }
2068
2069 static Sg_request *
2070 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2071 {
2072         Sg_request *resp;
2073         unsigned long iflags;
2074
2075         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2076         list_for_each_entry(resp, &sfp->rq_list, entry) {
2077                 /* look for requests that are ready + not SG_IO owned */
2078                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2079                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2080                         resp->done = 2; /* guard against other readers */
2081                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2082                         return resp;
2083                 }
2084         }
2085         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2086         return NULL;
2087 }
2088
2089 /* always adds to end of list */
2090 static Sg_request *
2091 sg_add_request(Sg_fd * sfp)
2092 {
2093         int k;
2094         unsigned long iflags;
2095         Sg_request *rp = sfp->req_arr;
2096
2097         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2098         if (!list_empty(&sfp->rq_list)) {
2099                 if (!sfp->cmd_q)
2100                         goto out_unlock;
2101
2102                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2103                         if (!rp->parentfp)
2104                                 break;
2105                 }
2106                 if (k >= SG_MAX_QUEUE)
2107                         goto out_unlock;
2108         }
2109         memset(rp, 0, sizeof (Sg_request));
2110         rp->parentfp = sfp;
2111         rp->header.duration = jiffies_to_msecs(jiffies);
2112         list_add_tail(&rp->entry, &sfp->rq_list);
2113         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2114         return rp;
2115 out_unlock:
2116         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2117         return NULL;
2118 }
2119
2120 /* Return of 1 for found; 0 for not found */
2121 static int
2122 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2123 {
2124         unsigned long iflags;
2125         int res = 0;
2126
2127         if (!sfp || !srp || list_empty(&sfp->rq_list))
2128                 return res;
2129         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2130         if (!list_empty(&srp->entry)) {
2131                 list_del(&srp->entry);
2132                 srp->parentfp = NULL;
2133                 res = 1;
2134         }
2135         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2136         return res;
2137 }
2138
2139 static Sg_fd *
2140 sg_add_sfp(Sg_device * sdp)
2141 {
2142         Sg_fd *sfp;
2143         unsigned long iflags;
2144         int bufflen;
2145
2146         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2147         if (!sfp)
2148                 return ERR_PTR(-ENOMEM);
2149
2150         init_waitqueue_head(&sfp->read_wait);
2151         rwlock_init(&sfp->rq_list_lock);
2152         INIT_LIST_HEAD(&sfp->rq_list);
2153         kref_init(&sfp->f_ref);
2154         mutex_init(&sfp->f_mutex);
2155         sfp->timeout = SG_DEFAULT_TIMEOUT;
2156         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2157         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2158         sfp->cmd_q = SG_DEF_COMMAND_Q;
2159         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2160         sfp->parentdp = sdp;
2161         write_lock_irqsave(&sdp->sfd_lock, iflags);
2162         if (atomic_read(&sdp->detaching)) {
2163                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2164                 return ERR_PTR(-ENODEV);
2165         }
2166         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2167         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2168         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2169                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2170         if (unlikely(sg_big_buff != def_reserved_size))
2171                 sg_big_buff = def_reserved_size;
2172
2173         bufflen = min_t(int, sg_big_buff,
2174                         max_sectors_bytes(sdp->device->request_queue));
2175         sg_build_reserve(sfp, bufflen);
2176         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2177                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2178                                       sfp->reserve.bufflen,
2179                                       sfp->reserve.k_use_sg));
2180
2181         kref_get(&sdp->d_ref);
2182         __module_get(THIS_MODULE);
2183         return sfp;
2184 }
2185
2186 static void
2187 sg_remove_sfp_usercontext(struct work_struct *work)
2188 {
2189         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2190         struct sg_device *sdp = sfp->parentdp;
2191         Sg_request *srp;
2192         unsigned long iflags;
2193
2194         /* Cleanup any responses which were never read(). */
2195         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2196         while (!list_empty(&sfp->rq_list)) {
2197                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2198                 sg_finish_rem_req(srp);
2199                 list_del(&srp->entry);
2200                 srp->parentfp = NULL;
2201         }
2202         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2203
2204         if (sfp->reserve.bufflen > 0) {
2205                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2206                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2207                                 (int) sfp->reserve.bufflen,
2208                                 (int) sfp->reserve.k_use_sg));
2209                 sg_remove_scat(sfp, &sfp->reserve);
2210         }
2211
2212         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2213                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2214         kfree(sfp);
2215
2216         scsi_device_put(sdp->device);
2217         kref_put(&sdp->d_ref, sg_device_destroy);
2218         module_put(THIS_MODULE);
2219 }
2220
2221 static void
2222 sg_remove_sfp(struct kref *kref)
2223 {
2224         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2225         struct sg_device *sdp = sfp->parentdp;
2226         unsigned long iflags;
2227
2228         write_lock_irqsave(&sdp->sfd_lock, iflags);
2229         list_del(&sfp->sfd_siblings);
2230         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2231
2232         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2233         schedule_work(&sfp->ew.work);
2234 }
2235
2236 #ifdef CONFIG_SCSI_PROC_FS
2237 static int
2238 sg_idr_max_id(int id, void *p, void *data)
2239 {
2240         int *k = data;
2241
2242         if (*k < id)
2243                 *k = id;
2244
2245         return 0;
2246 }
2247
2248 static int
2249 sg_last_dev(void)
2250 {
2251         int k = -1;
2252         unsigned long iflags;
2253
2254         read_lock_irqsave(&sg_index_lock, iflags);
2255         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2256         read_unlock_irqrestore(&sg_index_lock, iflags);
2257         return k + 1;           /* origin 1 */
2258 }
2259 #endif
2260
2261 /* must be called with sg_index_lock held */
2262 static Sg_device *sg_lookup_dev(int dev)
2263 {
2264         return idr_find(&sg_index_idr, dev);
2265 }
2266
2267 static Sg_device *
2268 sg_get_dev(int dev)
2269 {
2270         struct sg_device *sdp;
2271         unsigned long flags;
2272
2273         read_lock_irqsave(&sg_index_lock, flags);
2274         sdp = sg_lookup_dev(dev);
2275         if (!sdp)
2276                 sdp = ERR_PTR(-ENXIO);
2277         else if (atomic_read(&sdp->detaching)) {
2278                 /* If sdp->detaching, then the refcount may already be 0, in
2279                  * which case it would be a bug to do kref_get().
2280                  */
2281                 sdp = ERR_PTR(-ENODEV);
2282         } else
2283                 kref_get(&sdp->d_ref);
2284         read_unlock_irqrestore(&sg_index_lock, flags);
2285
2286         return sdp;
2287 }
2288
2289 #ifdef CONFIG_SCSI_PROC_FS
2290
2291 static struct proc_dir_entry *sg_proc_sgp = NULL;
2292
2293 static char sg_proc_sg_dirname[] = "scsi/sg";
2294
2295 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2296
2297 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2298 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2299                                   size_t count, loff_t *off);
2300 static const struct file_operations adio_fops = {
2301         .owner = THIS_MODULE,
2302         .open = sg_proc_single_open_adio,
2303         .read = seq_read,
2304         .llseek = seq_lseek,
2305         .write = sg_proc_write_adio,
2306         .release = single_release,
2307 };
2308
2309 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2310 static ssize_t sg_proc_write_dressz(struct file *filp,
2311                 const char __user *buffer, size_t count, loff_t *off);
2312 static const struct file_operations dressz_fops = {
2313         .owner = THIS_MODULE,
2314         .open = sg_proc_single_open_dressz,
2315         .read = seq_read,
2316         .llseek = seq_lseek,
2317         .write = sg_proc_write_dressz,
2318         .release = single_release,
2319 };
2320
2321 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2322 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2323 static const struct file_operations version_fops = {
2324         .owner = THIS_MODULE,
2325         .open = sg_proc_single_open_version,
2326         .read = seq_read,
2327         .llseek = seq_lseek,
2328         .release = single_release,
2329 };
2330
2331 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2332 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2333 static const struct file_operations devhdr_fops = {
2334         .owner = THIS_MODULE,
2335         .open = sg_proc_single_open_devhdr,
2336         .read = seq_read,
2337         .llseek = seq_lseek,
2338         .release = single_release,
2339 };
2340
2341 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2342 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2343 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2344 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2345 static void dev_seq_stop(struct seq_file *s, void *v);
2346 static const struct file_operations dev_fops = {
2347         .owner = THIS_MODULE,
2348         .open = sg_proc_open_dev,
2349         .read = seq_read,
2350         .llseek = seq_lseek,
2351         .release = seq_release,
2352 };
2353 static const struct seq_operations dev_seq_ops = {
2354         .start = dev_seq_start,
2355         .next  = dev_seq_next,
2356         .stop  = dev_seq_stop,
2357         .show  = sg_proc_seq_show_dev,
2358 };
2359
2360 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2361 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2362 static const struct file_operations devstrs_fops = {
2363         .owner = THIS_MODULE,
2364         .open = sg_proc_open_devstrs,
2365         .read = seq_read,
2366         .llseek = seq_lseek,
2367         .release = seq_release,
2368 };
2369 static const struct seq_operations devstrs_seq_ops = {
2370         .start = dev_seq_start,
2371         .next  = dev_seq_next,
2372         .stop  = dev_seq_stop,
2373         .show  = sg_proc_seq_show_devstrs,
2374 };
2375
2376 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2377 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2378 static const struct file_operations debug_fops = {
2379         .owner = THIS_MODULE,
2380         .open = sg_proc_open_debug,
2381         .read = seq_read,
2382         .llseek = seq_lseek,
2383         .release = seq_release,
2384 };
2385 static const struct seq_operations debug_seq_ops = {
2386         .start = dev_seq_start,
2387         .next  = dev_seq_next,
2388         .stop  = dev_seq_stop,
2389         .show  = sg_proc_seq_show_debug,
2390 };
2391
2392
2393 struct sg_proc_leaf {
2394         const char * name;
2395         const struct file_operations * fops;
2396 };
2397
2398 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2399         {"allow_dio", &adio_fops},
2400         {"debug", &debug_fops},
2401         {"def_reserved_size", &dressz_fops},
2402         {"device_hdr", &devhdr_fops},
2403         {"devices", &dev_fops},
2404         {"device_strs", &devstrs_fops},
2405         {"version", &version_fops}
2406 };
2407
2408 static int
2409 sg_proc_init(void)
2410 {
2411         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2412         int k;
2413
2414         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2415         if (!sg_proc_sgp)
2416                 return 1;
2417         for (k = 0; k < num_leaves; ++k) {
2418                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2419                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2420                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2421         }
2422         return 0;
2423 }
2424
2425 static void
2426 sg_proc_cleanup(void)
2427 {
2428         int k;
2429         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2430
2431         if (!sg_proc_sgp)
2432                 return;
2433         for (k = 0; k < num_leaves; ++k)
2434                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2435         remove_proc_entry(sg_proc_sg_dirname, NULL);
2436 }
2437
2438
2439 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2440 {
2441         seq_printf(s, "%d\n", *((int *)s->private));
2442         return 0;
2443 }
2444
2445 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2446 {
2447         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2448 }
2449
2450 static ssize_t
2451 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2452                    size_t count, loff_t *off)
2453 {
2454         int err;
2455         unsigned long num;
2456
2457         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2458                 return -EACCES;
2459         err = kstrtoul_from_user(buffer, count, 0, &num);
2460         if (err)
2461                 return err;
2462         sg_allow_dio = num ? 1 : 0;
2463         return count;
2464 }
2465
2466 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2467 {
2468         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2469 }
2470
2471 static ssize_t
2472 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2473                      size_t count, loff_t *off)
2474 {
2475         int err;
2476         unsigned long k = ULONG_MAX;
2477
2478         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2479                 return -EACCES;
2480
2481         err = kstrtoul_from_user(buffer, count, 0, &k);
2482         if (err)
2483                 return err;
2484         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2485                 sg_big_buff = k;
2486                 return count;
2487         }
2488         return -ERANGE;
2489 }
2490
2491 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2492 {
2493         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2494                    sg_version_date);
2495         return 0;
2496 }
2497
2498 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2499 {
2500         return single_open(file, sg_proc_seq_show_version, NULL);
2501 }
2502
2503 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2504 {
2505         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2506         return 0;
2507 }
2508
2509 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2510 {
2511         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2512 }
2513
2514 struct sg_proc_deviter {
2515         loff_t  index;
2516         size_t  max;
2517 };
2518
2519 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2520 {
2521         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2522
2523         s->private = it;
2524         if (! it)
2525                 return NULL;
2526
2527         it->index = *pos;
2528         it->max = sg_last_dev();
2529         if (it->index >= it->max)
2530                 return NULL;
2531         return it;
2532 }
2533
2534 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2535 {
2536         struct sg_proc_deviter * it = s->private;
2537
2538         *pos = ++it->index;
2539         return (it->index < it->max) ? it : NULL;
2540 }
2541
2542 static void dev_seq_stop(struct seq_file *s, void *v)
2543 {
2544         kfree(s->private);
2545 }
2546
2547 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2548 {
2549         return seq_open(file, &dev_seq_ops);
2550 }
2551
2552 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2553 {
2554         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2555         Sg_device *sdp;
2556         struct scsi_device *scsidp;
2557         unsigned long iflags;
2558
2559         read_lock_irqsave(&sg_index_lock, iflags);
2560         sdp = it ? sg_lookup_dev(it->index) : NULL;
2561         if ((NULL == sdp) || (NULL == sdp->device) ||
2562             (atomic_read(&sdp->detaching)))
2563                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2564         else {
2565                 scsidp = sdp->device;
2566                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2567                               scsidp->host->host_no, scsidp->channel,
2568                               scsidp->id, scsidp->lun, (int) scsidp->type,
2569                               1,
2570                               (int) scsidp->queue_depth,
2571                               (int) atomic_read(&scsidp->device_busy),
2572                               (int) scsi_device_online(scsidp));
2573         }
2574         read_unlock_irqrestore(&sg_index_lock, iflags);
2575         return 0;
2576 }
2577
2578 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2579 {
2580         return seq_open(file, &devstrs_seq_ops);
2581 }
2582
2583 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2584 {
2585         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2586         Sg_device *sdp;
2587         struct scsi_device *scsidp;
2588         unsigned long iflags;
2589
2590         read_lock_irqsave(&sg_index_lock, iflags);
2591         sdp = it ? sg_lookup_dev(it->index) : NULL;
2592         scsidp = sdp ? sdp->device : NULL;
2593         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2594                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2595                            scsidp->vendor, scsidp->model, scsidp->rev);
2596         else
2597                 seq_puts(s, "<no active device>\n");
2598         read_unlock_irqrestore(&sg_index_lock, iflags);
2599         return 0;
2600 }
2601
2602 /* must be called while holding sg_index_lock */
2603 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2604 {
2605         int k, new_interface, blen, usg;
2606         Sg_request *srp;
2607         Sg_fd *fp;
2608         const sg_io_hdr_t *hp;
2609         const char * cp;
2610         unsigned int ms;
2611
2612         k = 0;
2613         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2614                 k++;
2615                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2616                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2617                            "(res)sgat=%d low_dma=%d\n", k,
2618                            jiffies_to_msecs(fp->timeout),
2619                            fp->reserve.bufflen,
2620                            (int) fp->reserve.k_use_sg,
2621                            (int) sdp->device->host->unchecked_isa_dma);
2622                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2623                            (int) fp->cmd_q, (int) fp->force_packid,
2624                            (int) fp->keep_orphan);
2625                 list_for_each_entry(srp, &fp->rq_list, entry) {
2626                         hp = &srp->header;
2627                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2628                         if (srp->res_used) {
2629                                 if (new_interface &&
2630                                     (SG_FLAG_MMAP_IO & hp->flags))
2631                                         cp = "     mmap>> ";
2632                                 else
2633                                         cp = "     rb>> ";
2634                         } else {
2635                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2636                                         cp = "     dio>> ";
2637                                 else
2638                                         cp = "     ";
2639                         }
2640                         seq_puts(s, cp);
2641                         blen = srp->data.bufflen;
2642                         usg = srp->data.k_use_sg;
2643                         seq_puts(s, srp->done ?
2644                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2645                                   : "act:");
2646                         seq_printf(s, " id=%d blen=%d",
2647                                    srp->header.pack_id, blen);
2648                         if (srp->done)
2649                                 seq_printf(s, " dur=%d", hp->duration);
2650                         else {
2651                                 ms = jiffies_to_msecs(jiffies);
2652                                 seq_printf(s, " t_o/elap=%d/%d",
2653                                         (new_interface ? hp->timeout :
2654                                                   jiffies_to_msecs(fp->timeout)),
2655                                         (ms > hp->duration ? ms - hp->duration : 0));
2656                         }
2657                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2658                                    (int) srp->data.cmd_opcode);
2659                 }
2660                 if (list_empty(&fp->rq_list))
2661                         seq_puts(s, "     No requests active\n");
2662                 read_unlock(&fp->rq_list_lock);
2663         }
2664 }
2665
2666 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2667 {
2668         return seq_open(file, &debug_seq_ops);
2669 }
2670
2671 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2672 {
2673         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2674         Sg_device *sdp;
2675         unsigned long iflags;
2676
2677         if (it && (0 == it->index))
2678                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2679                            (int)it->max, sg_big_buff);
2680
2681         read_lock_irqsave(&sg_index_lock, iflags);
2682         sdp = it ? sg_lookup_dev(it->index) : NULL;
2683         if (NULL == sdp)
2684                 goto skip;
2685         read_lock(&sdp->sfd_lock);
2686         if (!list_empty(&sdp->sfds)) {
2687                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2688                 if (atomic_read(&sdp->detaching))
2689                         seq_puts(s, "detaching pending close ");
2690                 else if (sdp->device) {
2691                         struct scsi_device *scsidp = sdp->device;
2692
2693                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2694                                    scsidp->host->host_no,
2695                                    scsidp->channel, scsidp->id,
2696                                    scsidp->lun,
2697                                    scsidp->host->hostt->emulated);
2698                 }
2699                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2700                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2701                 sg_proc_debug_helper(s, sdp);
2702         }
2703         read_unlock(&sdp->sfd_lock);
2704 skip:
2705         read_unlock_irqrestore(&sg_index_lock, iflags);
2706         return 0;
2707 }
2708
2709 #endif                          /* CONFIG_SCSI_PROC_FS */
2710
2711 module_init(init_sg);
2712 module_exit(exit_sg);