drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct list_head entry; /* list entry */
 126         struct sg_fd *parentfp; /* NULL -> not in use */
 127         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 128         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 129         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 131         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 132         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 133         /* done protected by rq_list_lock */
 134         char done;              /* 0->before bh, 1->before read, 2->read */
 135         struct request *rq;
 136         struct bio *bio;
 137         struct execute_work ew;
 138 } Sg_request;
 139
 140 typedef struct sg_fd {          /* holds the state of a file descriptor */
 141         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142         struct sg_device *parentdp;     /* owning device */
 143         wait_queue_head_t read_wait;    /* queue read until command done */
 144         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 145         struct mutex f_mutex;   /* protect against changes in this fd */
 146         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 147         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 148         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 149         struct list_head rq_list; /* head of request list */
 150         struct fasync_struct *async_qp; /* used by asynchronous notification */
 151         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 153         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 154         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 155         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 156         char mmap_called;       /* 0 -> mmap() never called on this fd */
 157         char res_in_use;        /* 1 -> 'reserve' array in use */
 158         struct kref f_ref;
 159         struct execute_work ew;
 160 } Sg_fd;
 161
 162 typedef struct sg_device { /* holds the state of each scsi generic device */
 163         struct scsi_device *device;
 164         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165         struct mutex open_rel_lock;     /* held when in open() or release() */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         struct list_head sfds;
 169         rwlock_t sfd_lock;      /* protect access to sfd list */
 170         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 172         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static int sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static Sg_device *sg_get_dev(int dev);
 202 static void sg_device_destroy(struct kref *kref);
 203
 204 #define SZ_SG_HEADER sizeof(struct sg_header)
 205 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 206 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 207 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 208
 209 #define sg_printk(prefix, sdp, fmt, a...) \
 210         sdev_prefix_printk(prefix, (sdp)->device,               \
 211                            (sdp)->disk->disk_name, fmt, ##a)
 212
 213 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 214 {
 215         struct sg_fd *sfp = filp->private_data;
 216
 217         if (sfp->parentdp->device->type == TYPE_SCANNER)
 218                 return 0;
 219
 220         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 221 }
 222
 223 static int
 224 open_wait(Sg_device *sdp, int flags)
 225 {
 226         int retval = 0;
 227
 228         if (flags & O_EXCL) {
 229                 while (sdp->open_cnt > 0) {
 230                         mutex_unlock(&sdp->open_rel_lock);
 231                         retval = wait_event_interruptible(sdp->open_wait,
 232                                         (atomic_read(&sdp->detaching) ||
 233                                          !sdp->open_cnt));
 234                         mutex_lock(&sdp->open_rel_lock);
 235
 236                         if (retval) /* -ERESTARTSYS */
 237                                 return retval;
 238                         if (atomic_read(&sdp->detaching))
 239                                 return -ENODEV;
 240                 }
 241         } else {
 242                 while (sdp->exclude) {
 243                         mutex_unlock(&sdp->open_rel_lock);
 244                         retval = wait_event_interruptible(sdp->open_wait,
 245                                         (atomic_read(&sdp->detaching) ||
 246                                          !sdp->exclude));
 247                         mutex_lock(&sdp->open_rel_lock);
 248
 249                         if (retval) /* -ERESTARTSYS */
 250                                 return retval;
 251                         if (atomic_read(&sdp->detaching))
 252                                 return -ENODEV;
 253                 }
 254         }
 255
 256         return retval;
 257 }
 258
 259 /* Returns 0 on success, else a negated errno value */
 260 static int
 261 sg_open(struct inode *inode, struct file *filp)
 262 {
 263         int dev = iminor(inode);
 264         int flags = filp->f_flags;
 265         struct request_queue *q;
 266         Sg_device *sdp;
 267         Sg_fd *sfp;
 268         int retval;
 269
 270         nonseekable_open(inode, filp);
 271         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 272                 return -EPERM; /* Can't lock it with read only access */
 273         sdp = sg_get_dev(dev);
 274         if (IS_ERR(sdp))
 275                 return PTR_ERR(sdp);
 276
 277         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 278                                       "sg_open: flags=0x%x\n", flags));
 279
 280         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 281         /* Prevent the device driver from vanishing while we sleep */
 282         retval = scsi_device_get(sdp->device);
 283         if (retval)
 284                 goto sg_put;
 285
 286         retval = scsi_autopm_get_device(sdp->device);
 287         if (retval)
 288                 goto sdp_put;
 289
 290         /* scsi_block_when_processing_errors() may block so bypass
 291          * check if O_NONBLOCK. Permits SCSI commands to be issued
 292          * during error recovery. Tread carefully. */
 293         if (!((flags & O_NONBLOCK) ||
 294               scsi_block_when_processing_errors(sdp->device))) {
 295                 retval = -ENXIO;
 296                 /* we are in error recovery for this device */
 297                 goto error_out;
 298         }
 299
 300         mutex_lock(&sdp->open_rel_lock);
 301         if (flags & O_NONBLOCK) {
 302                 if (flags & O_EXCL) {
 303                         if (sdp->open_cnt > 0) {
 304                                 retval = -EBUSY;
 305                                 goto error_mutex_locked;
 306                         }
 307                 } else {
 308                         if (sdp->exclude) {
 309                                 retval = -EBUSY;
 310                                 goto error_mutex_locked;
 311                         }
 312                 }
 313         } else {
 314                 retval = open_wait(sdp, flags);
 315                 if (retval) /* -ERESTARTSYS or -ENODEV */
 316                         goto error_mutex_locked;
 317         }
 318
 319         /* N.B. at this point we are holding the open_rel_lock */
 320         if (flags & O_EXCL)
 321                 sdp->exclude = true;
 322
 323         if (sdp->open_cnt < 1) {  /* no existing opens */
 324                 sdp->sgdebug = 0;
 325                 q = sdp->device->request_queue;
 326                 sdp->sg_tablesize = queue_max_segments(q);
 327         }
 328         sfp = sg_add_sfp(sdp);
 329         if (IS_ERR(sfp)) {
 330                 retval = PTR_ERR(sfp);
 331                 goto out_undo;
 332         }
 333
 334         filp->private_data = sfp;
 335         sdp->open_cnt++;
 336         mutex_unlock(&sdp->open_rel_lock);
 337
 338         retval = 0;
 339 sg_put:
 340         kref_put(&sdp->d_ref, sg_device_destroy);
 341         return retval;
 342
 343 out_undo:
 344         if (flags & O_EXCL) {
 345                 sdp->exclude = false;   /* undo if error */
 346                 wake_up_interruptible(&sdp->open_wait);
 347         }
 348 error_mutex_locked:
 349         mutex_unlock(&sdp->open_rel_lock);
 350 error_out:
 351         scsi_autopm_put_device(sdp->device);
 352 sdp_put:
 353         scsi_device_put(sdp->device);
 354         goto sg_put;
 355 }
 356
 357 /* Release resources associated with a successful sg_open()
 358  * Returns 0 on success, else a negated errno value */
 359 static int
 360 sg_release(struct inode *inode, struct file *filp)
 361 {
 362         Sg_device *sdp;
 363         Sg_fd *sfp;
 364
 365         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 366                 return -ENXIO;
 367         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 368
 369         mutex_lock(&sdp->open_rel_lock);
 370         scsi_autopm_put_device(sdp->device);
 371         kref_put(&sfp->f_ref, sg_remove_sfp);
 372         sdp->open_cnt--;
 373
 374         /* possibly many open()s waiting on exlude clearing, start many;
 375          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 376         if (sdp->exclude) {
 377                 sdp->exclude = false;
 378                 wake_up_interruptible_all(&sdp->open_wait);
 379         } else if (0 == sdp->open_cnt) {
 380                 wake_up_interruptible(&sdp->open_wait);
 381         }
 382         mutex_unlock(&sdp->open_rel_lock);
 383         return 0;
 384 }
 385
 386 static ssize_t
 387 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 388 {
 389         Sg_device *sdp;
 390         Sg_fd *sfp;
 391         Sg_request *srp;
 392         int req_pack_id = -1;
 393         sg_io_hdr_t *hp;
 394         struct sg_header *old_hdr = NULL;
 395         int retval = 0;
 396
 397         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 398                 return -ENXIO;
 399         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 400                                       "sg_read: count=%d\n", (int) count));
 401
 402         if (!access_ok(VERIFY_WRITE, buf, count))
 403                 return -EFAULT;
 404         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 405                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 406                 if (!old_hdr)
 407                         return -ENOMEM;
 408                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 409                         retval = -EFAULT;
 410                         goto free_old_hdr;
 411                 }
 412                 if (old_hdr->reply_len < 0) {
 413                         if (count >= SZ_SG_IO_HDR) {
 414                                 sg_io_hdr_t *new_hdr;
 415                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 416                                 if (!new_hdr) {
 417                                         retval = -ENOMEM;
 418                                         goto free_old_hdr;
 419                                 }
 420                                 retval =__copy_from_user
 421                                     (new_hdr, buf, SZ_SG_IO_HDR);
 422                                 req_pack_id = new_hdr->pack_id;
 423                                 kfree(new_hdr);
 424                                 if (retval) {
 425                                         retval = -EFAULT;
 426                                         goto free_old_hdr;
 427                                 }
 428                         }
 429                 } else
 430                         req_pack_id = old_hdr->pack_id;
 431         }
 432         srp = sg_get_rq_mark(sfp, req_pack_id);
 433         if (!srp) {             /* now wait on packet to arrive */
 434                 if (atomic_read(&sdp->detaching)) {
 435                         retval = -ENODEV;
 436                         goto free_old_hdr;
 437                 }
 438                 if (filp->f_flags & O_NONBLOCK) {
 439                         retval = -EAGAIN;
 440                         goto free_old_hdr;
 441                 }
 442                 retval = wait_event_interruptible(sfp->read_wait,
 443                         (atomic_read(&sdp->detaching) ||
 444                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 445                 if (atomic_read(&sdp->detaching)) {
 446                         retval = -ENODEV;
 447                         goto free_old_hdr;
 448                 }
 449                 if (retval) {
 450                         /* -ERESTARTSYS as signal hit process */
 451                         goto free_old_hdr;
 452                 }
 453         }
 454         if (srp->header.interface_id != '\0') {
 455                 retval = sg_new_read(sfp, buf, count, srp);
 456                 goto free_old_hdr;
 457         }
 458
 459         hp = &srp->header;
 460         if (old_hdr == NULL) {
 461                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 462                 if (! old_hdr) {
 463                         retval = -ENOMEM;
 464                         goto free_old_hdr;
 465                 }
 466         }
 467         memset(old_hdr, 0, SZ_SG_HEADER);
 468         old_hdr->reply_len = (int) hp->timeout;
 469         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 470         old_hdr->pack_id = hp->pack_id;
 471         old_hdr->twelve_byte =
 472             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 473         old_hdr->target_status = hp->masked_status;
 474         old_hdr->host_status = hp->host_status;
 475         old_hdr->driver_status = hp->driver_status;
 476         if ((CHECK_CONDITION & hp->masked_status) ||
 477             (DRIVER_SENSE & hp->driver_status))
 478                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 479                        sizeof (old_hdr->sense_buffer));
 480         switch (hp->host_status) {
 481         /* This setup of 'result' is for backward compatibility and is best
 482            ignored by the user who should use target, host + driver status */
 483         case DID_OK:
 484         case DID_PASSTHROUGH:
 485         case DID_SOFT_ERROR:
 486                 old_hdr->result = 0;
 487                 break;
 488         case DID_NO_CONNECT:
 489         case DID_BUS_BUSY:
 490         case DID_TIME_OUT:
 491                 old_hdr->result = EBUSY;
 492                 break;
 493         case DID_BAD_TARGET:
 494         case DID_ABORT:
 495         case DID_PARITY:
 496         case DID_RESET:
 497         case DID_BAD_INTR:
 498                 old_hdr->result = EIO;
 499                 break;
 500         case DID_ERROR:
 501                 old_hdr->result = (srp->sense_b[0] == 0 &&
 502                                   hp->masked_status == GOOD) ? 0 : EIO;
 503                 break;
 504         default:
 505                 old_hdr->result = EIO;
 506                 break;
 507         }
 508
 509         /* Now copy the result back to the user buffer.  */
 510         if (count >= SZ_SG_HEADER) {
 511                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 512                         retval = -EFAULT;
 513                         goto free_old_hdr;
 514                 }
 515                 buf += SZ_SG_HEADER;
 516                 if (count > old_hdr->reply_len)
 517                         count = old_hdr->reply_len;
 518                 if (count > SZ_SG_HEADER) {
 519                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 520                                 retval = -EFAULT;
 521                                 goto free_old_hdr;
 522                         }
 523                 }
 524         } else
 525                 count = (old_hdr->result == 0) ? 0 : -EIO;
 526         sg_finish_rem_req(srp);
 527         sg_remove_request(sfp, srp);
 528         retval = count;
 529 free_old_hdr:
 530         kfree(old_hdr);
 531         return retval;
 532 }
 533
 534 static ssize_t
 535 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 536 {
 537         sg_io_hdr_t *hp = &srp->header;
 538         int err = 0, err2;
 539         int len;
 540
 541         if (count < SZ_SG_IO_HDR) {
 542                 err = -EINVAL;
 543                 goto err_out;
 544         }
 545         hp->sb_len_wr = 0;
 546         if ((hp->mx_sb_len > 0) && hp->sbp) {
 547                 if ((CHECK_CONDITION & hp->masked_status) ||
 548                     (DRIVER_SENSE & hp->driver_status)) {
 549                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 550                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 551                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 552                         len = (len > sb_len) ? sb_len : len;
 553                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 554                                 err = -EFAULT;
 555                                 goto err_out;
 556                         }
 557                         hp->sb_len_wr = len;
 558                 }
 559         }
 560         if (hp->masked_status || hp->host_status || hp->driver_status)
 561                 hp->info |= SG_INFO_CHECK;
 562         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 563                 err = -EFAULT;
 564                 goto err_out;
 565         }
 566 err_out:
 567         err2 = sg_finish_rem_req(srp);
 568         sg_remove_request(sfp, srp);
 569         return err ? : err2 ? : count;
 570 }
 571
 572 static ssize_t
 573 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 574 {
 575         int mxsize, cmd_size, k;
 576         int input_size, blocking;
 577         unsigned char opcode;
 578         Sg_device *sdp;
 579         Sg_fd *sfp;
 580         Sg_request *srp;
 581         struct sg_header old_hdr;
 582         sg_io_hdr_t *hp;
 583         unsigned char cmnd[SG_MAX_CDB_SIZE];
 584
 585         if (unlikely(uaccess_kernel()))
 586                 return -EINVAL;
 587
 588         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 589                 return -ENXIO;
 590         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 591                                       "sg_write: count=%d\n", (int) count));
 592         if (atomic_read(&sdp->detaching))
 593                 return -ENODEV;
 594         if (!((filp->f_flags & O_NONBLOCK) ||
 595               scsi_block_when_processing_errors(sdp->device)))
 596                 return -ENXIO;
 597
 598         if (!access_ok(VERIFY_READ, buf, count))
 599                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 600         if (count < SZ_SG_HEADER)
 601                 return -EIO;
 602         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 603                 return -EFAULT;
 604         blocking = !(filp->f_flags & O_NONBLOCK);
 605         if (old_hdr.reply_len < 0)
 606                 return sg_new_write(sfp, filp, buf, count,
 607                                     blocking, 0, 0, NULL);
 608         if (count < (SZ_SG_HEADER + 6))
 609                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 610
 611         if (!(srp = sg_add_request(sfp))) {
 612                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 613                                               "sg_write: queue full\n"));
 614                 return -EDOM;
 615         }
 616         buf += SZ_SG_HEADER;
 617         __get_user(opcode, buf);
 618         mutex_lock(&sfp->f_mutex);
 619         if (sfp->next_cmd_len > 0) {
 620                 cmd_size = sfp->next_cmd_len;
 621                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 622         } else {
 623                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 624                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 625                         cmd_size = 12;
 626         }
 627         mutex_unlock(&sfp->f_mutex);
 628         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 629                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 630 /* Determine buffer size.  */
 631         input_size = count - cmd_size;
 632         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 633         mxsize -= SZ_SG_HEADER;
 634         input_size -= SZ_SG_HEADER;
 635         if (input_size < 0) {
 636                 sg_remove_request(sfp, srp);
 637                 return -EIO;    /* User did not pass enough bytes for this command. */
 638         }
 639         hp = &srp->header;
 640         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 641         hp->cmd_len = (unsigned char) cmd_size;
 642         hp->iovec_count = 0;
 643         hp->mx_sb_len = 0;
 644         if (input_size > 0)
 645                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 646                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 647         else
 648                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 649         hp->dxfer_len = mxsize;
 650         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 651             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 652                 hp->dxferp = (char __user *)buf + cmd_size;
 653         else
 654                 hp->dxferp = NULL;
 655         hp->sbp = NULL;
 656         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 657         hp->flags = input_size; /* structure abuse ... */
 658         hp->pack_id = old_hdr.pack_id;
 659         hp->usr_ptr = NULL;
 660         if (__copy_from_user(cmnd, buf, cmd_size))
 661                 return -EFAULT;
 662         /*
 663          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 664          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 665          * is a non-zero input_size, so emit a warning.
 666          */
 667         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 668                 printk_ratelimited(KERN_WARNING
 669                                    "sg_write: data in/out %d/%d bytes "
 670                                    "for SCSI command 0x%x-- guessing "
 671                                    "data in;\n   program %s not setting "
 672                                    "count and/or reply_len properly\n",
 673                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 674                                    input_size, (unsigned int) cmnd[0],
 675                                    current->comm);
 676         }
 677         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 678         return (k < 0) ? k : count;
 679 }
 680
 681 static ssize_t
 682 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 683                  size_t count, int blocking, int read_only, int sg_io_owned,
 684                  Sg_request **o_srp)
 685 {
 686         int k;
 687         Sg_request *srp;
 688         sg_io_hdr_t *hp;
 689         unsigned char cmnd[SG_MAX_CDB_SIZE];
 690         int timeout;
 691         unsigned long ul_timeout;
 692
 693         if (count < SZ_SG_IO_HDR)
 694                 return -EINVAL;
 695         if (!access_ok(VERIFY_READ, buf, count))
 696                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 697
 698         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 699         if (!(srp = sg_add_request(sfp))) {
 700                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 701                                               "sg_new_write: queue full\n"));
 702                 return -EDOM;
 703         }
 704         srp->sg_io_owned = sg_io_owned;
 705         hp = &srp->header;
 706         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 707                 sg_remove_request(sfp, srp);
 708                 return -EFAULT;
 709         }
 710         if (hp->interface_id != 'S') {
 711                 sg_remove_request(sfp, srp);
 712                 return -ENOSYS;
 713         }
 714         if (hp->flags & SG_FLAG_MMAP_IO) {
 715                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 716                         sg_remove_request(sfp, srp);
 717                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 718                 }
 719                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 720                         sg_remove_request(sfp, srp);
 721                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 722                 }
 723                 if (sfp->res_in_use) {
 724                         sg_remove_request(sfp, srp);
 725                         return -EBUSY;  /* reserve buffer already being used */
 726                 }
 727         }
 728         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 729         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 730         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 731                 sg_remove_request(sfp, srp);
 732                 return -EMSGSIZE;
 733         }
 734         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 735                 sg_remove_request(sfp, srp);
 736                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 737         }
 738         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 739                 sg_remove_request(sfp, srp);
 740                 return -EFAULT;
 741         }
 742         if (read_only && sg_allow_access(file, cmnd)) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EPERM;
 745         }
 746         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 747         if (k < 0)
 748                 return k;
 749         if (o_srp)
 750                 *o_srp = srp;
 751         return count;
 752 }
 753
 754 static int
 755 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 756                 unsigned char *cmnd, int timeout, int blocking)
 757 {
 758         int k, at_head;
 759         Sg_device *sdp = sfp->parentdp;
 760         sg_io_hdr_t *hp = &srp->header;
 761
 762         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 763         hp->status = 0;
 764         hp->masked_status = 0;
 765         hp->msg_status = 0;
 766         hp->info = 0;
 767         hp->host_status = 0;
 768         hp->driver_status = 0;
 769         hp->resid = 0;
 770         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 771                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 772                         (int) cmnd[0], (int) hp->cmd_len));
 773
 774         if (hp->dxfer_len >= SZ_256M)
 775                 return -EINVAL;
 776
 777         k = sg_start_req(srp, cmnd);
 778         if (k) {
 779                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 780                         "sg_common_write: start_req err=%d\n", k));
 781                 sg_finish_rem_req(srp);
 782                 sg_remove_request(sfp, srp);
 783                 return k;       /* probably out of space --> ENOMEM */
 784         }
 785         if (atomic_read(&sdp->detaching)) {
 786                 if (srp->bio) {
 787                         scsi_req_free_cmd(scsi_req(srp->rq));
 788                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 789                         srp->rq = NULL;
 790                 }
 791
 792                 sg_finish_rem_req(srp);
 793                 sg_remove_request(sfp, srp);
 794                 return -ENODEV;
 795         }
 796
 797         hp->duration = jiffies_to_msecs(jiffies);
 798         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 799             (SG_FLAG_Q_AT_TAIL & hp->flags))
 800                 at_head = 0;
 801         else
 802                 at_head = 1;
 803
 804         srp->rq->timeout = timeout;
 805         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 806         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 807                               srp->rq, at_head, sg_rq_end_io);
 808         return 0;
 809 }
 810
 811 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 812 {
 813         unsigned long flags;
 814         int ret;
 815
 816         read_lock_irqsave(&sfp->rq_list_lock, flags);
 817         ret = srp->done;
 818         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 819         return ret;
 820 }
 821
 822 static int max_sectors_bytes(struct request_queue *q)
 823 {
 824         unsigned int max_sectors = queue_max_sectors(q);
 825
 826         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 827
 828         return max_sectors << 9;
 829 }
 830
 831 static long
 832 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 833 {
 834         void __user *p = (void __user *)arg;
 835         int __user *ip = p;
 836         int result, val, read_only;
 837         Sg_device *sdp;
 838         Sg_fd *sfp;
 839         Sg_request *srp;
 840         unsigned long iflags;
 841
 842         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 843                 return -ENXIO;
 844
 845         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 846                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 847         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 848
 849         switch (cmd_in) {
 850         case SG_IO:
 851                 if (atomic_read(&sdp->detaching))
 852                         return -ENODEV;
 853                 if (!scsi_block_when_processing_errors(sdp->device))
 854                         return -ENXIO;
 855                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 856                         return -EFAULT;
 857                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 858                                  1, read_only, 1, &srp);
 859                 if (result < 0)
 860                         return result;
 861                 result = wait_event_interruptible(sfp->read_wait,
 862                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 863                 if (atomic_read(&sdp->detaching))
 864                         return -ENODEV;
 865                 write_lock_irq(&sfp->rq_list_lock);
 866                 if (srp->done) {
 867                         srp->done = 2;
 868                         write_unlock_irq(&sfp->rq_list_lock);
 869                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 870                         return (result < 0) ? result : 0;
 871                 }
 872                 srp->orphan = 1;
 873                 write_unlock_irq(&sfp->rq_list_lock);
 874                 return result;  /* -ERESTARTSYS because signal hit process */
 875         case SG_SET_TIMEOUT:
 876                 result = get_user(val, ip);
 877                 if (result)
 878                         return result;
 879                 if (val < 0)
 880                         return -EIO;
 881                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 882                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 883                                     INT_MAX);
 884                 sfp->timeout_user = val;
 885                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 886
 887                 return 0;
 888         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 889                                 /* strange ..., for backward compatibility */
 890                 return sfp->timeout_user;
 891         case SG_SET_FORCE_LOW_DMA:
 892                 /*
 893                  * N.B. This ioctl never worked properly, but failed to
 894                  * return an error value. So returning '0' to keep compability
 895                  * with legacy applications.
 896                  */
 897                 return 0;
 898         case SG_GET_LOW_DMA:
 899                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 900         case SG_GET_SCSI_ID:
 901                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 902                         return -EFAULT;
 903                 else {
 904                         sg_scsi_id_t __user *sg_idp = p;
 905
 906                         if (atomic_read(&sdp->detaching))
 907                                 return -ENODEV;
 908                         __put_user((int) sdp->device->host->host_no,
 909                                    &sg_idp->host_no);
 910                         __put_user((int) sdp->device->channel,
 911                                    &sg_idp->channel);
 912                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 913                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 914                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 915                         __put_user((short) sdp->device->host->cmd_per_lun,
 916                                    &sg_idp->h_cmd_per_lun);
 917                         __put_user((short) sdp->device->queue_depth,
 918                                    &sg_idp->d_queue_depth);
 919                         __put_user(0, &sg_idp->unused[0]);
 920                         __put_user(0, &sg_idp->unused[1]);
 921                         return 0;
 922                 }
 923         case SG_SET_FORCE_PACK_ID:
 924                 result = get_user(val, ip);
 925                 if (result)
 926                         return result;
 927                 sfp->force_packid = val ? 1 : 0;
 928                 return 0;
 929         case SG_GET_PACK_ID:
 930                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 931                         return -EFAULT;
 932                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 933                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 934                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 935                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 936                                                        iflags);
 937                                 __put_user(srp->header.pack_id, ip);
 938                                 return 0;
 939                         }
 940                 }
 941                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 942                 __put_user(-1, ip);
 943                 return 0;
 944         case SG_GET_NUM_WAITING:
 945                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 946                 val = 0;
 947                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 948                         if ((1 == srp->done) && (!srp->sg_io_owned))
 949                                 ++val;
 950                 }
 951                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 952                 return put_user(val, ip);
 953         case SG_GET_SG_TABLESIZE:
 954                 return put_user(sdp->sg_tablesize, ip);
 955         case SG_SET_RESERVED_SIZE:
 956                 result = get_user(val, ip);
 957                 if (result)
 958                         return result;
 959                 if (val < 0)
 960                         return -EINVAL;
 961                 val = min_t(int, val,
 962                             max_sectors_bytes(sdp->device->request_queue));
 963                 mutex_lock(&sfp->f_mutex);
 964                 if (val != sfp->reserve.bufflen) {
 965                         if (sfp->mmap_called ||
 966                             sfp->res_in_use) {
 967                                 mutex_unlock(&sfp->f_mutex);
 968                                 return -EBUSY;
 969                         }
 970
 971                         sg_remove_scat(sfp, &sfp->reserve);
 972                         sg_build_reserve(sfp, val);
 973                 }
 974                 mutex_unlock(&sfp->f_mutex);
 975                 return 0;
 976         case SG_GET_RESERVED_SIZE:
 977                 val = min_t(int, sfp->reserve.bufflen,
 978                             max_sectors_bytes(sdp->device->request_queue));
 979                 return put_user(val, ip);
 980         case SG_SET_COMMAND_Q:
 981                 result = get_user(val, ip);
 982                 if (result)
 983                         return result;
 984                 sfp->cmd_q = val ? 1 : 0;
 985                 return 0;
 986         case SG_GET_COMMAND_Q:
 987                 return put_user((int) sfp->cmd_q, ip);
 988         case SG_SET_KEEP_ORPHAN:
 989                 result = get_user(val, ip);
 990                 if (result)
 991                         return result;
 992                 sfp->keep_orphan = val;
 993                 return 0;
 994         case SG_GET_KEEP_ORPHAN:
 995                 return put_user((int) sfp->keep_orphan, ip);
 996         case SG_NEXT_CMD_LEN:
 997                 result = get_user(val, ip);
 998                 if (result)
 999                         return result;
1000                 if (val > SG_MAX_CDB_SIZE)
1001                         return -ENOMEM;
1002                 sfp->next_cmd_len = (val > 0) ? val : 0;
1003                 return 0;
1004         case SG_GET_VERSION_NUM:
1005                 return put_user(sg_version_num, ip);
1006         case SG_GET_ACCESS_COUNT:
1007                 /* faked - we don't have a real access count anymore */
1008                 val = (sdp->device ? 1 : 0);
1009                 return put_user(val, ip);
1010         case SG_GET_REQUEST_TABLE:
1011                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1012                         return -EFAULT;
1013                 else {
1014                         sg_req_info_t *rinfo;
1015                         unsigned int ms;
1016
1017                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1018                                                                 GFP_KERNEL);
1019                         if (!rinfo)
1020                                 return -ENOMEM;
1021                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1022                         val = 0;
1023                         list_for_each_entry(srp, &sfp->rq_list, entry) {
1024                                 if (val >= SG_MAX_QUEUE)
1025                                         break;
1026                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1027                                 rinfo[val].req_state = srp->done + 1;
1028                                 rinfo[val].problem =
1029                                         srp->header.masked_status &
1030                                         srp->header.host_status &
1031                                         srp->header.driver_status;
1032                                 if (srp->done)
1033                                         rinfo[val].duration =
1034                                                 srp->header.duration;
1035                                 else {
1036                                         ms = jiffies_to_msecs(jiffies);
1037                                         rinfo[val].duration =
1038                                                 (ms > srp->header.duration) ?
1039                                                 (ms - srp->header.duration) : 0;
1040                                 }
1041                                 rinfo[val].orphan = srp->orphan;
1042                                 rinfo[val].sg_io_owned = srp->sg_io_owned;
1043                                 rinfo[val].pack_id = srp->header.pack_id;
1044                                 rinfo[val].usr_ptr = srp->header.usr_ptr;
1045                                 val++;
1046                         }
1047                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1048                         result = __copy_to_user(p, rinfo,
1049                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1050                         result = result ? -EFAULT : 0;
1051                         kfree(rinfo);
1052                         return result;
1053                 }
1054         case SG_EMULATED_HOST:
1055                 if (atomic_read(&sdp->detaching))
1056                         return -ENODEV;
1057                 return put_user(sdp->device->host->hostt->emulated, ip);
1058         case SCSI_IOCTL_SEND_COMMAND:
1059                 if (atomic_read(&sdp->detaching))
1060                         return -ENODEV;
1061                 if (read_only) {
1062                         unsigned char opcode = WRITE_6;
1063                         Scsi_Ioctl_Command __user *siocp = p;
1064
1065                         if (copy_from_user(&opcode, siocp->data, 1))
1066                                 return -EFAULT;
1067                         if (sg_allow_access(filp, &opcode))
1068                                 return -EPERM;
1069                 }
1070                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1071         case SG_SET_DEBUG:
1072                 result = get_user(val, ip);
1073                 if (result)
1074                         return result;
1075                 sdp->sgdebug = (char) val;
1076                 return 0;
1077         case BLKSECTGET:
1078                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1079                                 ip);
1080         case BLKTRACESETUP:
1081                 return blk_trace_setup(sdp->device->request_queue,
1082                                        sdp->disk->disk_name,
1083                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1084                                        NULL, p);
1085         case BLKTRACESTART:
1086                 return blk_trace_startstop(sdp->device->request_queue, 1);
1087         case BLKTRACESTOP:
1088                 return blk_trace_startstop(sdp->device->request_queue, 0);
1089         case BLKTRACETEARDOWN:
1090                 return blk_trace_remove(sdp->device->request_queue);
1091         case SCSI_IOCTL_GET_IDLUN:
1092         case SCSI_IOCTL_GET_BUS_NUMBER:
1093         case SCSI_IOCTL_PROBE_HOST:
1094         case SG_GET_TRANSFORM:
1095         case SG_SCSI_RESET:
1096                 if (atomic_read(&sdp->detaching))
1097                         return -ENODEV;
1098                 break;
1099         default:
1100                 if (read_only)
1101                         return -EPERM;  /* don't know so take safe approach */
1102                 break;
1103         }
1104
1105         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1106                         cmd_in, filp->f_flags & O_NDELAY);
1107         if (result)
1108                 return result;
1109         return scsi_ioctl(sdp->device, cmd_in, p);
1110 }
1111
1112 #ifdef CONFIG_COMPAT
1113 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1114 {
1115         Sg_device *sdp;
1116         Sg_fd *sfp;
1117         struct scsi_device *sdev;
1118
1119         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1120                 return -ENXIO;
1121
1122         sdev = sdp->device;
1123         if (sdev->host->hostt->compat_ioctl) {
1124                 int ret;
1125
1126                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1127
1128                 return ret;
1129         }
1130
1131         return -ENOIOCTLCMD;
1132 }
1133 #endif
1134
1135 static unsigned int
1136 sg_poll(struct file *filp, poll_table * wait)
1137 {
1138         unsigned int res = 0;
1139         Sg_device *sdp;
1140         Sg_fd *sfp;
1141         Sg_request *srp;
1142         int count = 0;
1143         unsigned long iflags;
1144
1145         sfp = filp->private_data;
1146         if (!sfp)
1147                 return POLLERR;
1148         sdp = sfp->parentdp;
1149         if (!sdp)
1150                 return POLLERR;
1151         poll_wait(filp, &sfp->read_wait, wait);
1152         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1153         list_for_each_entry(srp, &sfp->rq_list, entry) {
1154                 /* if any read waiting, flag it */
1155                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1156                         res = POLLIN | POLLRDNORM;
1157                 ++count;
1158         }
1159         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1160
1161         if (atomic_read(&sdp->detaching))
1162                 res |= POLLHUP;
1163         else if (!sfp->cmd_q) {
1164                 if (0 == count)
1165                         res |= POLLOUT | POLLWRNORM;
1166         } else if (count < SG_MAX_QUEUE)
1167                 res |= POLLOUT | POLLWRNORM;
1168         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1169                                       "sg_poll: res=0x%x\n", (int) res));
1170         return res;
1171 }
1172
1173 static int
1174 sg_fasync(int fd, struct file *filp, int mode)
1175 {
1176         Sg_device *sdp;
1177         Sg_fd *sfp;
1178
1179         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1180                 return -ENXIO;
1181         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1182                                       "sg_fasync: mode=%d\n", mode));
1183
1184         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1185 }
1186
1187 static int
1188 sg_vma_fault(struct vm_fault *vmf)
1189 {
1190         struct vm_area_struct *vma = vmf->vma;
1191         Sg_fd *sfp;
1192         unsigned long offset, len, sa;
1193         Sg_scatter_hold *rsv_schp;
1194         int k, length;
1195
1196         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1197                 return VM_FAULT_SIGBUS;
1198         rsv_schp = &sfp->reserve;
1199         offset = vmf->pgoff << PAGE_SHIFT;
1200         if (offset >= rsv_schp->bufflen)
1201                 return VM_FAULT_SIGBUS;
1202         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1203                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1204                                       offset, rsv_schp->k_use_sg));
1205         sa = vma->vm_start;
1206         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1207         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1208                 len = vma->vm_end - sa;
1209                 len = (len < length) ? len : length;
1210                 if (offset < len) {
1211                         struct page *page = nth_page(rsv_schp->pages[k],
1212                                                      offset >> PAGE_SHIFT);
1213                         get_page(page); /* increment page count */
1214                         vmf->page = page;
1215                         return 0; /* success */
1216                 }
1217                 sa += len;
1218                 offset -= len;
1219         }
1220
1221         return VM_FAULT_SIGBUS;
1222 }
1223
1224 static const struct vm_operations_struct sg_mmap_vm_ops = {
1225         .fault = sg_vma_fault,
1226 };
1227
1228 static int
1229 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1230 {
1231         Sg_fd *sfp;
1232         unsigned long req_sz, len, sa;
1233         Sg_scatter_hold *rsv_schp;
1234         int k, length;
1235         int ret = 0;
1236
1237         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1238                 return -ENXIO;
1239         req_sz = vma->vm_end - vma->vm_start;
1240         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1241                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1242                                       (void *) vma->vm_start, (int) req_sz));
1243         if (vma->vm_pgoff)
1244                 return -EINVAL; /* want no offset */
1245         rsv_schp = &sfp->reserve;
1246         mutex_lock(&sfp->f_mutex);
1247         if (req_sz > rsv_schp->bufflen) {
1248                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1249                 goto out;
1250         }
1251
1252         sa = vma->vm_start;
1253         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1254         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1255                 len = vma->vm_end - sa;
1256                 len = (len < length) ? len : length;
1257                 sa += len;
1258         }
1259
1260         sfp->mmap_called = 1;
1261         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1262         vma->vm_private_data = sfp;
1263         vma->vm_ops = &sg_mmap_vm_ops;
1264 out:
1265         mutex_unlock(&sfp->f_mutex);
1266         return ret;
1267 }
1268
1269 static void
1270 sg_rq_end_io_usercontext(struct work_struct *work)
1271 {
1272         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1273         struct sg_fd *sfp = srp->parentfp;
1274
1275         sg_finish_rem_req(srp);
1276         sg_remove_request(sfp, srp);
1277         kref_put(&sfp->f_ref, sg_remove_sfp);
1278 }
1279
1280 /*
1281  * This function is a "bottom half" handler that is called by the mid
1282  * level when a command is completed (or has failed).
1283  */
1284 static void
1285 sg_rq_end_io(struct request *rq, blk_status_t status)
1286 {
1287         struct sg_request *srp = rq->end_io_data;
1288         struct scsi_request *req = scsi_req(rq);
1289         Sg_device *sdp;
1290         Sg_fd *sfp;
1291         unsigned long iflags;
1292         unsigned int ms;
1293         char *sense;
1294         int result, resid, done = 1;
1295
1296         if (WARN_ON(srp->done != 0))
1297                 return;
1298
1299         sfp = srp->parentfp;
1300         if (WARN_ON(sfp == NULL))
1301                 return;
1302
1303         sdp = sfp->parentdp;
1304         if (unlikely(atomic_read(&sdp->detaching)))
1305                 pr_info("%s: device detaching\n", __func__);
1306
1307         sense = req->sense;
1308         result = req->result;
1309         resid = req->resid_len;
1310
1311         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1312                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1313                                       srp->header.pack_id, result));
1314         srp->header.resid = resid;
1315         ms = jiffies_to_msecs(jiffies);
1316         srp->header.duration = (ms > srp->header.duration) ?
1317                                 (ms - srp->header.duration) : 0;
1318         if (0 != result) {
1319                 struct scsi_sense_hdr sshdr;
1320
1321                 srp->header.status = 0xff & result;
1322                 srp->header.masked_status = status_byte(result);
1323                 srp->header.msg_status = msg_byte(result);
1324                 srp->header.host_status = host_byte(result);
1325                 srp->header.driver_status = driver_byte(result);
1326                 if ((sdp->sgdebug > 0) &&
1327                     ((CHECK_CONDITION == srp->header.masked_status) ||
1328                      (COMMAND_TERMINATED == srp->header.masked_status)))
1329                         __scsi_print_sense(sdp->device, __func__, sense,
1330                                            SCSI_SENSE_BUFFERSIZE);
1331
1332                 /* Following if statement is a patch supplied by Eric Youngdale */
1333                 if (driver_byte(result) != 0
1334                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1335                     && !scsi_sense_is_deferred(&sshdr)
1336                     && sshdr.sense_key == UNIT_ATTENTION
1337                     && sdp->device->removable) {
1338                         /* Detected possible disc change. Set the bit - this */
1339                         /* may be used if there are filesystems using this device */
1340                         sdp->device->changed = 1;
1341                 }
1342         }
1343
1344         if (req->sense_len)
1345                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1346
1347         /* Rely on write phase to clean out srp status values, so no "else" */
1348
1349         /*
1350          * Free the request as soon as it is complete so that its resources
1351          * can be reused without waiting for userspace to read() the
1352          * result.  But keep the associated bio (if any) around until
1353          * blk_rq_unmap_user() can be called from user context.
1354          */
1355         srp->rq = NULL;
1356         scsi_req_free_cmd(scsi_req(rq));
1357         __blk_put_request(rq->q, rq);
1358
1359         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1360         if (unlikely(srp->orphan)) {
1361                 if (sfp->keep_orphan)
1362                         srp->sg_io_owned = 0;
1363                 else
1364                         done = 0;
1365         }
1366         srp->done = done;
1367         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1368
1369         if (likely(done)) {
1370                 /* Now wake up any sg_read() that is waiting for this
1371                  * packet.
1372                  */
1373                 wake_up_interruptible(&sfp->read_wait);
1374                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1375                 kref_put(&sfp->f_ref, sg_remove_sfp);
1376         } else {
1377                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1378                 schedule_work(&srp->ew.work);
1379         }
1380 }
1381
1382 static const struct file_operations sg_fops = {
1383         .owner = THIS_MODULE,
1384         .read = sg_read,
1385         .write = sg_write,
1386         .poll = sg_poll,
1387         .unlocked_ioctl = sg_ioctl,
1388 #ifdef CONFIG_COMPAT
1389         .compat_ioctl = sg_compat_ioctl,
1390 #endif
1391         .open = sg_open,
1392         .mmap = sg_mmap,
1393         .release = sg_release,
1394         .fasync = sg_fasync,
1395         .llseek = no_llseek,
1396 };
1397
1398 static struct class *sg_sysfs_class;
1399
1400 static int sg_sysfs_valid = 0;
1401
1402 static Sg_device *
1403 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1404 {
1405         struct request_queue *q = scsidp->request_queue;
1406         Sg_device *sdp;
1407         unsigned long iflags;
1408         int error;
1409         u32 k;
1410
1411         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1412         if (!sdp) {
1413                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1414                             "failure\n", __func__);
1415                 return ERR_PTR(-ENOMEM);
1416         }
1417
1418         idr_preload(GFP_KERNEL);
1419         write_lock_irqsave(&sg_index_lock, iflags);
1420
1421         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1422         if (error < 0) {
1423                 if (error == -ENOSPC) {
1424                         sdev_printk(KERN_WARNING, scsidp,
1425                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1426                                     scsidp->type, SG_MAX_DEVS - 1);
1427                         error = -ENODEV;
1428                 } else {
1429                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1430                                     "allocation Sg_device failure: %d\n",
1431                                     __func__, error);
1432                 }
1433                 goto out_unlock;
1434         }
1435         k = error;
1436
1437         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1438                                         "sg_alloc: dev=%d \n", k));
1439         sprintf(disk->disk_name, "sg%d", k);
1440         disk->first_minor = k;
1441         sdp->disk = disk;
1442         sdp->device = scsidp;
1443         mutex_init(&sdp->open_rel_lock);
1444         INIT_LIST_HEAD(&sdp->sfds);
1445         init_waitqueue_head(&sdp->open_wait);
1446         atomic_set(&sdp->detaching, 0);
1447         rwlock_init(&sdp->sfd_lock);
1448         sdp->sg_tablesize = queue_max_segments(q);
1449         sdp->index = k;
1450         kref_init(&sdp->d_ref);
1451         error = 0;
1452
1453 out_unlock:
1454         write_unlock_irqrestore(&sg_index_lock, iflags);
1455         idr_preload_end();
1456
1457         if (error) {
1458                 kfree(sdp);
1459                 return ERR_PTR(error);
1460         }
1461         return sdp;
1462 }
1463
1464 static int
1465 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1466 {
1467         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1468         struct gendisk *disk;
1469         Sg_device *sdp = NULL;
1470         struct cdev * cdev = NULL;
1471         int error;
1472         unsigned long iflags;
1473
1474         disk = alloc_disk(1);
1475         if (!disk) {
1476                 pr_warn("%s: alloc_disk failed\n", __func__);
1477                 return -ENOMEM;
1478         }
1479         disk->major = SCSI_GENERIC_MAJOR;
1480
1481         error = -ENOMEM;
1482         cdev = cdev_alloc();
1483         if (!cdev) {
1484                 pr_warn("%s: cdev_alloc failed\n", __func__);
1485                 goto out;
1486         }
1487         cdev->owner = THIS_MODULE;
1488         cdev->ops = &sg_fops;
1489
1490         sdp = sg_alloc(disk, scsidp);
1491         if (IS_ERR(sdp)) {
1492                 pr_warn("%s: sg_alloc failed\n", __func__);
1493                 error = PTR_ERR(sdp);
1494                 goto out;
1495         }
1496
1497         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1498         if (error)
1499                 goto cdev_add_err;
1500
1501         sdp->cdev = cdev;
1502         if (sg_sysfs_valid) {
1503                 struct device *sg_class_member;
1504
1505                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1506                                                 MKDEV(SCSI_GENERIC_MAJOR,
1507                                                       sdp->index),
1508                                                 sdp, "%s", disk->disk_name);
1509                 if (IS_ERR(sg_class_member)) {
1510                         pr_err("%s: device_create failed\n", __func__);
1511                         error = PTR_ERR(sg_class_member);
1512                         goto cdev_add_err;
1513                 }
1514                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1515                                           &sg_class_member->kobj, "generic");
1516                 if (error)
1517                         pr_err("%s: unable to make symlink 'generic' back "
1518                                "to sg%d\n", __func__, sdp->index);
1519         } else
1520                 pr_warn("%s: sg_sys Invalid\n", __func__);
1521
1522         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1523                     "type %d\n", sdp->index, scsidp->type);
1524
1525         dev_set_drvdata(cl_dev, sdp);
1526
1527         return 0;
1528
1529 cdev_add_err:
1530         write_lock_irqsave(&sg_index_lock, iflags);
1531         idr_remove(&sg_index_idr, sdp->index);
1532         write_unlock_irqrestore(&sg_index_lock, iflags);
1533         kfree(sdp);
1534
1535 out:
1536         put_disk(disk);
1537         if (cdev)
1538                 cdev_del(cdev);
1539         return error;
1540 }
1541
1542 static void
1543 sg_device_destroy(struct kref *kref)
1544 {
1545         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1546         unsigned long flags;
1547
1548         /* CAUTION!  Note that the device can still be found via idr_find()
1549          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1550          * any other cleanup.
1551          */
1552
1553         write_lock_irqsave(&sg_index_lock, flags);
1554         idr_remove(&sg_index_idr, sdp->index);
1555         write_unlock_irqrestore(&sg_index_lock, flags);
1556
1557         SCSI_LOG_TIMEOUT(3,
1558                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1559
1560         put_disk(sdp->disk);
1561         kfree(sdp);
1562 }
1563
1564 static void
1565 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1566 {
1567         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1568         Sg_device *sdp = dev_get_drvdata(cl_dev);
1569         unsigned long iflags;
1570         Sg_fd *sfp;
1571         int val;
1572
1573         if (!sdp)
1574                 return;
1575         /* want sdp->detaching non-zero as soon as possible */
1576         val = atomic_inc_return(&sdp->detaching);
1577         if (val > 1)
1578                 return; /* only want to do following once per device */
1579
1580         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1581                                       "%s\n", __func__));
1582
1583         read_lock_irqsave(&sdp->sfd_lock, iflags);
1584         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1585                 wake_up_interruptible_all(&sfp->read_wait);
1586                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1587         }
1588         wake_up_interruptible_all(&sdp->open_wait);
1589         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1590
1591         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1592         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1593         cdev_del(sdp->cdev);
1594         sdp->cdev = NULL;
1595
1596         kref_put(&sdp->d_ref, sg_device_destroy);
1597 }
1598
1599 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1600 module_param_named(def_reserved_size, def_reserved_size, int,
1601                    S_IRUGO | S_IWUSR);
1602 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1603
1604 MODULE_AUTHOR("Douglas Gilbert");
1605 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1606 MODULE_LICENSE("GPL");
1607 MODULE_VERSION(SG_VERSION_STR);
1608 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1609
1610 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1611                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1612 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1613 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1614
1615 static int __init
1616 init_sg(void)
1617 {
1618         int rc;
1619
1620         if (scatter_elem_sz < PAGE_SIZE) {
1621                 scatter_elem_sz = PAGE_SIZE;
1622                 scatter_elem_sz_prev = scatter_elem_sz;
1623         }
1624         if (def_reserved_size >= 0)
1625                 sg_big_buff = def_reserved_size;
1626         else
1627                 def_reserved_size = sg_big_buff;
1628
1629         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1630                                     SG_MAX_DEVS, "sg");
1631         if (rc)
1632                 return rc;
1633         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1634         if ( IS_ERR(sg_sysfs_class) ) {
1635                 rc = PTR_ERR(sg_sysfs_class);
1636                 goto err_out;
1637         }
1638         sg_sysfs_valid = 1;
1639         rc = scsi_register_interface(&sg_interface);
1640         if (0 == rc) {
1641 #ifdef CONFIG_SCSI_PROC_FS
1642                 sg_proc_init();
1643 #endif                          /* CONFIG_SCSI_PROC_FS */
1644                 return 0;
1645         }
1646         class_destroy(sg_sysfs_class);
1647 err_out:
1648         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1649         return rc;
1650 }
1651
1652 static void __exit
1653 exit_sg(void)
1654 {
1655 #ifdef CONFIG_SCSI_PROC_FS
1656         sg_proc_cleanup();
1657 #endif                          /* CONFIG_SCSI_PROC_FS */
1658         scsi_unregister_interface(&sg_interface);
1659         class_destroy(sg_sysfs_class);
1660         sg_sysfs_valid = 0;
1661         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1662                                  SG_MAX_DEVS);
1663         idr_destroy(&sg_index_idr);
1664 }
1665
1666 static int
1667 sg_start_req(Sg_request *srp, unsigned char *cmd)
1668 {
1669         int res;
1670         struct request *rq;
1671         struct scsi_request *req;
1672         Sg_fd *sfp = srp->parentfp;
1673         sg_io_hdr_t *hp = &srp->header;
1674         int dxfer_len = (int) hp->dxfer_len;
1675         int dxfer_dir = hp->dxfer_direction;
1676         unsigned int iov_count = hp->iovec_count;
1677         Sg_scatter_hold *req_schp = &srp->data;
1678         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1679         struct request_queue *q = sfp->parentdp->device->request_queue;
1680         struct rq_map_data *md, map_data;
1681         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1682         unsigned char *long_cmdp = NULL;
1683
1684         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1685                                       "sg_start_req: dxfer_len=%d\n",
1686                                       dxfer_len));
1687
1688         if (hp->cmd_len > BLK_MAX_CDB) {
1689                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1690                 if (!long_cmdp)
1691                         return -ENOMEM;
1692         }
1693
1694         /*
1695          * NOTE
1696          *
1697          * With scsi-mq enabled, there are a fixed number of preallocated
1698          * requests equal in number to shost->can_queue.  If all of the
1699          * preallocated requests are already in use, then using GFP_ATOMIC with
1700          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1701          * will cause blk_get_request() to sleep until an active command
1702          * completes, freeing up a request.  Neither option is ideal, but
1703          * GFP_KERNEL is the better choice to prevent userspace from getting an
1704          * unexpected EWOULDBLOCK.
1705          *
1706          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1707          * does not sleep except under memory pressure.
1708          */
1709         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1710                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1711         if (IS_ERR(rq)) {
1712                 kfree(long_cmdp);
1713                 return PTR_ERR(rq);
1714         }
1715         req = scsi_req(rq);
1716
1717         if (hp->cmd_len > BLK_MAX_CDB)
1718                 req->cmd = long_cmdp;
1719         memcpy(req->cmd, cmd, hp->cmd_len);
1720         req->cmd_len = hp->cmd_len;
1721
1722         srp->rq = rq;
1723         rq->end_io_data = srp;
1724         req->retries = SG_DEFAULT_RETRIES;
1725
1726         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1727                 return 0;
1728
1729         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1730             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1731             !sfp->parentdp->device->host->unchecked_isa_dma &&
1732             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1733                 md = NULL;
1734         else
1735                 md = &map_data;
1736
1737         if (md) {
1738                 mutex_lock(&sfp->f_mutex);
1739                 if (dxfer_len <= rsv_schp->bufflen &&
1740                     !sfp->res_in_use) {
1741                         sfp->res_in_use = 1;
1742                         sg_link_reserve(sfp, srp, dxfer_len);
1743                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1744                         res = -EBUSY; /* sfp->res_in_use == 1 */
1745                         if (dxfer_len > rsv_schp->bufflen)
1746                                 res = -ENOMEM;
1747                         mutex_unlock(&sfp->f_mutex);
1748                         return res;
1749                 } else {
1750                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1751                         if (res) {
1752                                 mutex_unlock(&sfp->f_mutex);
1753                                 return res;
1754                         }
1755                 }
1756                 mutex_unlock(&sfp->f_mutex);
1757
1758                 md->pages = req_schp->pages;
1759                 md->page_order = req_schp->page_order;
1760                 md->nr_entries = req_schp->k_use_sg;
1761                 md->offset = 0;
1762                 md->null_mapped = hp->dxferp ? 0 : 1;
1763                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1764                         md->from_user = 1;
1765                 else
1766                         md->from_user = 0;
1767         }
1768
1769         if (iov_count) {
1770                 struct iovec *iov = NULL;
1771                 struct iov_iter i;
1772
1773                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1774                 if (res < 0)
1775                         return res;
1776
1777                 iov_iter_truncate(&i, hp->dxfer_len);
1778                 if (!iov_iter_count(&i)) {
1779                         kfree(iov);
1780                         return -EINVAL;
1781                 }
1782
1783                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1784                 kfree(iov);
1785         } else
1786                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1787                                       hp->dxfer_len, GFP_ATOMIC);
1788
1789         if (!res) {
1790                 srp->bio = rq->bio;
1791
1792                 if (!md) {
1793                         req_schp->dio_in_use = 1;
1794                         hp->info |= SG_INFO_DIRECT_IO;
1795                 }
1796         }
1797         return res;
1798 }
1799
1800 static int
1801 sg_finish_rem_req(Sg_request *srp)
1802 {
1803         int ret = 0;
1804
1805         Sg_fd *sfp = srp->parentfp;
1806         Sg_scatter_hold *req_schp = &srp->data;
1807
1808         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1809                                       "sg_finish_rem_req: res_used=%d\n",
1810                                       (int) srp->res_used));
1811         if (srp->bio)
1812                 ret = blk_rq_unmap_user(srp->bio);
1813
1814         if (srp->rq) {
1815                 scsi_req_free_cmd(scsi_req(srp->rq));
1816                 blk_put_request(srp->rq);
1817         }
1818
1819         if (srp->res_used)
1820                 sg_unlink_reserve(sfp, srp);
1821         else
1822                 sg_remove_scat(sfp, req_schp);
1823
1824         return ret;
1825 }
1826
1827 static int
1828 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1829 {
1830         int sg_bufflen = tablesize * sizeof(struct page *);
1831         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1832
1833         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1834         if (!schp->pages)
1835                 return -ENOMEM;
1836         schp->sglist_len = sg_bufflen;
1837         return tablesize;       /* number of scat_gath elements allocated */
1838 }
1839
1840 static int
1841 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1842 {
1843         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1844         int sg_tablesize = sfp->parentdp->sg_tablesize;
1845         int blk_size = buff_size, order;
1846         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1847         struct sg_device *sdp = sfp->parentdp;
1848
1849         if (blk_size < 0)
1850                 return -EFAULT;
1851         if (0 == blk_size)
1852                 ++blk_size;     /* don't know why */
1853         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1854         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1855         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1856                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1857                 buff_size, blk_size));
1858
1859         /* N.B. ret_sz carried into this block ... */
1860         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1861         if (mx_sc_elems < 0)
1862                 return mx_sc_elems;     /* most likely -ENOMEM */
1863
1864         num = scatter_elem_sz;
1865         if (unlikely(num != scatter_elem_sz_prev)) {
1866                 if (num < PAGE_SIZE) {
1867                         scatter_elem_sz = PAGE_SIZE;
1868                         scatter_elem_sz_prev = PAGE_SIZE;
1869                 } else
1870                         scatter_elem_sz_prev = num;
1871         }
1872
1873         if (sdp->device->host->unchecked_isa_dma)
1874                 gfp_mask |= GFP_DMA;
1875
1876         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1877                 gfp_mask |= __GFP_ZERO;
1878
1879         order = get_order(num);
1880 retry:
1881         ret_sz = 1 << (PAGE_SHIFT + order);
1882
1883         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1884              k++, rem_sz -= ret_sz) {
1885
1886                 num = (rem_sz > scatter_elem_sz_prev) ?
1887                         scatter_elem_sz_prev : rem_sz;
1888
1889                 schp->pages[k] = alloc_pages(gfp_mask, order);
1890                 if (!schp->pages[k])
1891                         goto out;
1892
1893                 if (num == scatter_elem_sz_prev) {
1894                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1895                                 scatter_elem_sz = ret_sz;
1896                                 scatter_elem_sz_prev = ret_sz;
1897                         }
1898                 }
1899
1900                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1901                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1902                                  k, num, ret_sz));
1903         }               /* end of for loop */
1904
1905         schp->page_order = order;
1906         schp->k_use_sg = k;
1907         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1908                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1909                          k, rem_sz));
1910
1911         schp->bufflen = blk_size;
1912         if (rem_sz > 0) /* must have failed */
1913                 return -ENOMEM;
1914         return 0;
1915 out:
1916         for (i = 0; i < k; i++)
1917                 __free_pages(schp->pages[i], order);
1918
1919         if (--order >= 0)
1920                 goto retry;
1921
1922         return -ENOMEM;
1923 }
1924
1925 static void
1926 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1927 {
1928         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1929                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1930         if (schp->pages && schp->sglist_len > 0) {
1931                 if (!schp->dio_in_use) {
1932                         int k;
1933
1934                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1935                                 SCSI_LOG_TIMEOUT(5,
1936                                         sg_printk(KERN_INFO, sfp->parentdp,
1937                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1938                                         k, schp->pages[k]));
1939                                 __free_pages(schp->pages[k], schp->page_order);
1940                         }
1941
1942                         kfree(schp->pages);
1943                 }
1944         }
1945         memset(schp, 0, sizeof (*schp));
1946 }
1947
1948 static int
1949 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1950 {
1951         Sg_scatter_hold *schp = &srp->data;
1952         int k, num;
1953
1954         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1955                          "sg_read_oxfer: num_read_xfer=%d\n",
1956                          num_read_xfer));
1957         if ((!outp) || (num_read_xfer <= 0))
1958                 return 0;
1959
1960         num = 1 << (PAGE_SHIFT + schp->page_order);
1961         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1962                 if (num > num_read_xfer) {
1963                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1964                                            num_read_xfer))
1965                                 return -EFAULT;
1966                         break;
1967                 } else {
1968                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1969                                            num))
1970                                 return -EFAULT;
1971                         num_read_xfer -= num;
1972                         if (num_read_xfer <= 0)
1973                                 break;
1974                         outp += num;
1975                 }
1976         }
1977
1978         return 0;
1979 }
1980
1981 static void
1982 sg_build_reserve(Sg_fd * sfp, int req_size)
1983 {
1984         Sg_scatter_hold *schp = &sfp->reserve;
1985
1986         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1987                          "sg_build_reserve: req_size=%d\n", req_size));
1988         do {
1989                 if (req_size < PAGE_SIZE)
1990                         req_size = PAGE_SIZE;
1991                 if (0 == sg_build_indirect(schp, sfp, req_size))
1992                         return;
1993                 else
1994                         sg_remove_scat(sfp, schp);
1995                 req_size >>= 1; /* divide by 2 */
1996         } while (req_size > (PAGE_SIZE / 2));
1997 }
1998
1999 static void
2000 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2001 {
2002         Sg_scatter_hold *req_schp = &srp->data;
2003         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2004         int k, num, rem;
2005
2006         srp->res_used = 1;
2007         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2008                          "sg_link_reserve: size=%d\n", size));
2009         rem = size;
2010
2011         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2012         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2013                 if (rem <= num) {
2014                         req_schp->k_use_sg = k + 1;
2015                         req_schp->sglist_len = rsv_schp->sglist_len;
2016                         req_schp->pages = rsv_schp->pages;
2017
2018                         req_schp->bufflen = size;
2019                         req_schp->page_order = rsv_schp->page_order;
2020                         break;
2021                 } else
2022                         rem -= num;
2023         }
2024
2025         if (k >= rsv_schp->k_use_sg)
2026                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2027                                  "sg_link_reserve: BAD size\n"));
2028 }
2029
2030 static void
2031 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2032 {
2033         Sg_scatter_hold *req_schp = &srp->data;
2034
2035         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2036                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2037                                       (int) req_schp->k_use_sg));
2038         req_schp->k_use_sg = 0;
2039         req_schp->bufflen = 0;
2040         req_schp->pages = NULL;
2041         req_schp->page_order = 0;
2042         req_schp->sglist_len = 0;
2043         srp->res_used = 0;
2044         /* Called without mutex lock to avoid deadlock */
2045         sfp->res_in_use = 0;
2046 }
2047
2048 static Sg_request *
2049 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2050 {
2051         Sg_request *resp;
2052         unsigned long iflags;
2053
2054         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2055         list_for_each_entry(resp, &sfp->rq_list, entry) {
2056                 /* look for requests that are ready + not SG_IO owned */
2057                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2058                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2059                         resp->done = 2; /* guard against other readers */
2060                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2061                         return resp;
2062                 }
2063         }
2064         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2065         return NULL;
2066 }
2067
2068 /* always adds to end of list */
2069 static Sg_request *
2070 sg_add_request(Sg_fd * sfp)
2071 {
2072         int k;
2073         unsigned long iflags;
2074         Sg_request *rp = sfp->req_arr;
2075
2076         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2077         if (!list_empty(&sfp->rq_list)) {
2078                 if (!sfp->cmd_q)
2079                         goto out_unlock;
2080
2081                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2082                         if (!rp->parentfp)
2083                                 break;
2084                 }
2085                 if (k >= SG_MAX_QUEUE)
2086                         goto out_unlock;
2087         }
2088         memset(rp, 0, sizeof (Sg_request));
2089         rp->parentfp = sfp;
2090         rp->header.duration = jiffies_to_msecs(jiffies);
2091         list_add_tail(&rp->entry, &sfp->rq_list);
2092         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2093         return rp;
2094 out_unlock:
2095         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2096         return NULL;
2097 }
2098
2099 /* Return of 1 for found; 0 for not found */
2100 static int
2101 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2102 {
2103         unsigned long iflags;
2104         int res = 0;
2105
2106         if (!sfp || !srp || list_empty(&sfp->rq_list))
2107                 return res;
2108         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2109         if (!list_empty(&srp->entry)) {
2110                 list_del(&srp->entry);
2111                 srp->parentfp = NULL;
2112                 res = 1;
2113         }
2114         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2115         return res;
2116 }
2117
2118 static Sg_fd *
2119 sg_add_sfp(Sg_device * sdp)
2120 {
2121         Sg_fd *sfp;
2122         unsigned long iflags;
2123         int bufflen;
2124
2125         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2126         if (!sfp)
2127                 return ERR_PTR(-ENOMEM);
2128
2129         init_waitqueue_head(&sfp->read_wait);
2130         rwlock_init(&sfp->rq_list_lock);
2131         INIT_LIST_HEAD(&sfp->rq_list);
2132         kref_init(&sfp->f_ref);
2133         mutex_init(&sfp->f_mutex);
2134         sfp->timeout = SG_DEFAULT_TIMEOUT;
2135         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2136         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2137         sfp->cmd_q = SG_DEF_COMMAND_Q;
2138         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2139         sfp->parentdp = sdp;
2140         write_lock_irqsave(&sdp->sfd_lock, iflags);
2141         if (atomic_read(&sdp->detaching)) {
2142                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2143                 return ERR_PTR(-ENODEV);
2144         }
2145         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2146         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2147         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2148                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2149         if (unlikely(sg_big_buff != def_reserved_size))
2150                 sg_big_buff = def_reserved_size;
2151
2152         bufflen = min_t(int, sg_big_buff,
2153                         max_sectors_bytes(sdp->device->request_queue));
2154         sg_build_reserve(sfp, bufflen);
2155         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2156                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2157                                       sfp->reserve.bufflen,
2158                                       sfp->reserve.k_use_sg));
2159
2160         kref_get(&sdp->d_ref);
2161         __module_get(THIS_MODULE);
2162         return sfp;
2163 }
2164
2165 static void
2166 sg_remove_sfp_usercontext(struct work_struct *work)
2167 {
2168         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2169         struct sg_device *sdp = sfp->parentdp;
2170         Sg_request *srp;
2171         unsigned long iflags;
2172
2173         /* Cleanup any responses which were never read(). */
2174         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2175         while (!list_empty(&sfp->rq_list)) {
2176                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2177                 sg_finish_rem_req(srp);
2178                 list_del(&srp->entry);
2179                 srp->parentfp = NULL;
2180         }
2181         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2182
2183         if (sfp->reserve.bufflen > 0) {
2184                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2185                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2186                                 (int) sfp->reserve.bufflen,
2187                                 (int) sfp->reserve.k_use_sg));
2188                 sg_remove_scat(sfp, &sfp->reserve);
2189         }
2190
2191         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2192                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2193         kfree(sfp);
2194
2195         scsi_device_put(sdp->device);
2196         kref_put(&sdp->d_ref, sg_device_destroy);
2197         module_put(THIS_MODULE);
2198 }
2199
2200 static void
2201 sg_remove_sfp(struct kref *kref)
2202 {
2203         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2204         struct sg_device *sdp = sfp->parentdp;
2205         unsigned long iflags;
2206
2207         write_lock_irqsave(&sdp->sfd_lock, iflags);
2208         list_del(&sfp->sfd_siblings);
2209         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2210
2211         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2212         schedule_work(&sfp->ew.work);
2213 }
2214
2215 #ifdef CONFIG_SCSI_PROC_FS
2216 static int
2217 sg_idr_max_id(int id, void *p, void *data)
2218 {
2219         int *k = data;
2220
2221         if (*k < id)
2222                 *k = id;
2223
2224         return 0;
2225 }
2226
2227 static int
2228 sg_last_dev(void)
2229 {
2230         int k = -1;
2231         unsigned long iflags;
2232
2233         read_lock_irqsave(&sg_index_lock, iflags);
2234         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2235         read_unlock_irqrestore(&sg_index_lock, iflags);
2236         return k + 1;           /* origin 1 */
2237 }
2238 #endif
2239
2240 /* must be called with sg_index_lock held */
2241 static Sg_device *sg_lookup_dev(int dev)
2242 {
2243         return idr_find(&sg_index_idr, dev);
2244 }
2245
2246 static Sg_device *
2247 sg_get_dev(int dev)
2248 {
2249         struct sg_device *sdp;
2250         unsigned long flags;
2251
2252         read_lock_irqsave(&sg_index_lock, flags);
2253         sdp = sg_lookup_dev(dev);
2254         if (!sdp)
2255                 sdp = ERR_PTR(-ENXIO);
2256         else if (atomic_read(&sdp->detaching)) {
2257                 /* If sdp->detaching, then the refcount may already be 0, in
2258                  * which case it would be a bug to do kref_get().
2259                  */
2260                 sdp = ERR_PTR(-ENODEV);
2261         } else
2262                 kref_get(&sdp->d_ref);
2263         read_unlock_irqrestore(&sg_index_lock, flags);
2264
2265         return sdp;
2266 }
2267
2268 #ifdef CONFIG_SCSI_PROC_FS
2269
2270 static struct proc_dir_entry *sg_proc_sgp = NULL;
2271
2272 static char sg_proc_sg_dirname[] = "scsi/sg";
2273
2274 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2275
2276 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2277 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2278                                   size_t count, loff_t *off);
2279 static const struct file_operations adio_fops = {
2280         .owner = THIS_MODULE,
2281         .open = sg_proc_single_open_adio,
2282         .read = seq_read,
2283         .llseek = seq_lseek,
2284         .write = sg_proc_write_adio,
2285         .release = single_release,
2286 };
2287
2288 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2289 static ssize_t sg_proc_write_dressz(struct file *filp,
2290                 const char __user *buffer, size_t count, loff_t *off);
2291 static const struct file_operations dressz_fops = {
2292         .owner = THIS_MODULE,
2293         .open = sg_proc_single_open_dressz,
2294         .read = seq_read,
2295         .llseek = seq_lseek,
2296         .write = sg_proc_write_dressz,
2297         .release = single_release,
2298 };
2299
2300 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2301 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2302 static const struct file_operations version_fops = {
2303         .owner = THIS_MODULE,
2304         .open = sg_proc_single_open_version,
2305         .read = seq_read,
2306         .llseek = seq_lseek,
2307         .release = single_release,
2308 };
2309
2310 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2311 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2312 static const struct file_operations devhdr_fops = {
2313         .owner = THIS_MODULE,
2314         .open = sg_proc_single_open_devhdr,
2315         .read = seq_read,
2316         .llseek = seq_lseek,
2317         .release = single_release,
2318 };
2319
2320 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2321 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2322 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2323 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2324 static void dev_seq_stop(struct seq_file *s, void *v);
2325 static const struct file_operations dev_fops = {
2326         .owner = THIS_MODULE,
2327         .open = sg_proc_open_dev,
2328         .read = seq_read,
2329         .llseek = seq_lseek,
2330         .release = seq_release,
2331 };
2332 static const struct seq_operations dev_seq_ops = {
2333         .start = dev_seq_start,
2334         .next  = dev_seq_next,
2335         .stop  = dev_seq_stop,
2336         .show  = sg_proc_seq_show_dev,
2337 };
2338
2339 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2340 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2341 static const struct file_operations devstrs_fops = {
2342         .owner = THIS_MODULE,
2343         .open = sg_proc_open_devstrs,
2344         .read = seq_read,
2345         .llseek = seq_lseek,
2346         .release = seq_release,
2347 };
2348 static const struct seq_operations devstrs_seq_ops = {
2349         .start = dev_seq_start,
2350         .next  = dev_seq_next,
2351         .stop  = dev_seq_stop,
2352         .show  = sg_proc_seq_show_devstrs,
2353 };
2354
2355 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2356 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2357 static const struct file_operations debug_fops = {
2358         .owner = THIS_MODULE,
2359         .open = sg_proc_open_debug,
2360         .read = seq_read,
2361         .llseek = seq_lseek,
2362         .release = seq_release,
2363 };
2364 static const struct seq_operations debug_seq_ops = {
2365         .start = dev_seq_start,
2366         .next  = dev_seq_next,
2367         .stop  = dev_seq_stop,
2368         .show  = sg_proc_seq_show_debug,
2369 };
2370
2371
2372 struct sg_proc_leaf {
2373         const char * name;
2374         const struct file_operations * fops;
2375 };
2376
2377 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2378         {"allow_dio", &adio_fops},
2379         {"debug", &debug_fops},
2380         {"def_reserved_size", &dressz_fops},
2381         {"device_hdr", &devhdr_fops},
2382         {"devices", &dev_fops},
2383         {"device_strs", &devstrs_fops},
2384         {"version", &version_fops}
2385 };
2386
2387 static int
2388 sg_proc_init(void)
2389 {
2390         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2391         int k;
2392
2393         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2394         if (!sg_proc_sgp)
2395                 return 1;
2396         for (k = 0; k < num_leaves; ++k) {
2397                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2398                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2399                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2400         }
2401         return 0;
2402 }
2403
2404 static void
2405 sg_proc_cleanup(void)
2406 {
2407         int k;
2408         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2409
2410         if (!sg_proc_sgp)
2411                 return;
2412         for (k = 0; k < num_leaves; ++k)
2413                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2414         remove_proc_entry(sg_proc_sg_dirname, NULL);
2415 }
2416
2417
2418 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2419 {
2420         seq_printf(s, "%d\n", *((int *)s->private));
2421         return 0;
2422 }
2423
2424 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2425 {
2426         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2427 }
2428
2429 static ssize_t
2430 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2431                    size_t count, loff_t *off)
2432 {
2433         int err;
2434         unsigned long num;
2435
2436         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2437                 return -EACCES;
2438         err = kstrtoul_from_user(buffer, count, 0, &num);
2439         if (err)
2440                 return err;
2441         sg_allow_dio = num ? 1 : 0;
2442         return count;
2443 }
2444
2445 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2446 {
2447         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2448 }
2449
2450 static ssize_t
2451 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2452                      size_t count, loff_t *off)
2453 {
2454         int err;
2455         unsigned long k = ULONG_MAX;
2456
2457         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2458                 return -EACCES;
2459
2460         err = kstrtoul_from_user(buffer, count, 0, &k);
2461         if (err)
2462                 return err;
2463         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2464                 sg_big_buff = k;
2465                 return count;
2466         }
2467         return -ERANGE;
2468 }
2469
2470 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2471 {
2472         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2473                    sg_version_date);
2474         return 0;
2475 }
2476
2477 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2478 {
2479         return single_open(file, sg_proc_seq_show_version, NULL);
2480 }
2481
2482 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2483 {
2484         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2485         return 0;
2486 }
2487
2488 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2489 {
2490         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2491 }
2492
2493 struct sg_proc_deviter {
2494         loff_t  index;
2495         size_t  max;
2496 };
2497
2498 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2499 {
2500         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2501
2502         s->private = it;
2503         if (! it)
2504                 return NULL;
2505
2506         it->index = *pos;
2507         it->max = sg_last_dev();
2508         if (it->index >= it->max)
2509                 return NULL;
2510         return it;
2511 }
2512
2513 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2514 {
2515         struct sg_proc_deviter * it = s->private;
2516
2517         *pos = ++it->index;
2518         return (it->index < it->max) ? it : NULL;
2519 }
2520
2521 static void dev_seq_stop(struct seq_file *s, void *v)
2522 {
2523         kfree(s->private);
2524 }
2525
2526 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2527 {
2528         return seq_open(file, &dev_seq_ops);
2529 }
2530
2531 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2532 {
2533         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2534         Sg_device *sdp;
2535         struct scsi_device *scsidp;
2536         unsigned long iflags;
2537
2538         read_lock_irqsave(&sg_index_lock, iflags);
2539         sdp = it ? sg_lookup_dev(it->index) : NULL;
2540         if ((NULL == sdp) || (NULL == sdp->device) ||
2541             (atomic_read(&sdp->detaching)))
2542                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2543         else {
2544                 scsidp = sdp->device;
2545                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2546                               scsidp->host->host_no, scsidp->channel,
2547                               scsidp->id, scsidp->lun, (int) scsidp->type,
2548                               1,
2549                               (int) scsidp->queue_depth,
2550                               (int) atomic_read(&scsidp->device_busy),
2551                               (int) scsi_device_online(scsidp));
2552         }
2553         read_unlock_irqrestore(&sg_index_lock, iflags);
2554         return 0;
2555 }
2556
2557 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2558 {
2559         return seq_open(file, &devstrs_seq_ops);
2560 }
2561
2562 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2563 {
2564         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2565         Sg_device *sdp;
2566         struct scsi_device *scsidp;
2567         unsigned long iflags;
2568
2569         read_lock_irqsave(&sg_index_lock, iflags);
2570         sdp = it ? sg_lookup_dev(it->index) : NULL;
2571         scsidp = sdp ? sdp->device : NULL;
2572         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2573                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2574                            scsidp->vendor, scsidp->model, scsidp->rev);
2575         else
2576                 seq_puts(s, "<no active device>\n");
2577         read_unlock_irqrestore(&sg_index_lock, iflags);
2578         return 0;
2579 }
2580
2581 /* must be called while holding sg_index_lock */
2582 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2583 {
2584         int k, new_interface, blen, usg;
2585         Sg_request *srp;
2586         Sg_fd *fp;
2587         const sg_io_hdr_t *hp;
2588         const char * cp;
2589         unsigned int ms;
2590
2591         k = 0;
2592         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2593                 k++;
2594                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2595                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2596                            "(res)sgat=%d low_dma=%d\n", k,
2597                            jiffies_to_msecs(fp->timeout),
2598                            fp->reserve.bufflen,
2599                            (int) fp->reserve.k_use_sg,
2600                            (int) sdp->device->host->unchecked_isa_dma);
2601                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2602                            (int) fp->cmd_q, (int) fp->force_packid,
2603                            (int) fp->keep_orphan);
2604                 list_for_each_entry(srp, &fp->rq_list, entry) {
2605                         hp = &srp->header;
2606                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2607                         if (srp->res_used) {
2608                                 if (new_interface &&
2609                                     (SG_FLAG_MMAP_IO & hp->flags))
2610                                         cp = "     mmap>> ";
2611                                 else
2612                                         cp = "     rb>> ";
2613                         } else {
2614                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2615                                         cp = "     dio>> ";
2616                                 else
2617                                         cp = "     ";
2618                         }
2619                         seq_puts(s, cp);
2620                         blen = srp->data.bufflen;
2621                         usg = srp->data.k_use_sg;
2622                         seq_puts(s, srp->done ?
2623                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2624                                   : "act:");
2625                         seq_printf(s, " id=%d blen=%d",
2626                                    srp->header.pack_id, blen);
2627                         if (srp->done)
2628                                 seq_printf(s, " dur=%d", hp->duration);
2629                         else {
2630                                 ms = jiffies_to_msecs(jiffies);
2631                                 seq_printf(s, " t_o/elap=%d/%d",
2632                                         (new_interface ? hp->timeout :
2633                                                   jiffies_to_msecs(fp->timeout)),
2634                                         (ms > hp->duration ? ms - hp->duration : 0));
2635                         }
2636                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2637                                    (int) srp->data.cmd_opcode);
2638                 }
2639                 if (list_empty(&fp->rq_list))
2640                         seq_puts(s, "     No requests active\n");
2641                 read_unlock(&fp->rq_list_lock);
2642         }
2643 }
2644
2645 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2646 {
2647         return seq_open(file, &debug_seq_ops);
2648 }
2649
2650 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2651 {
2652         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2653         Sg_device *sdp;
2654         unsigned long iflags;
2655
2656         if (it && (0 == it->index))
2657                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2658                            (int)it->max, sg_big_buff);
2659
2660         read_lock_irqsave(&sg_index_lock, iflags);
2661         sdp = it ? sg_lookup_dev(it->index) : NULL;
2662         if (NULL == sdp)
2663                 goto skip;
2664         read_lock(&sdp->sfd_lock);
2665         if (!list_empty(&sdp->sfds)) {
2666                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2667                 if (atomic_read(&sdp->detaching))
2668                         seq_puts(s, "detaching pending close ");
2669                 else if (sdp->device) {
2670                         struct scsi_device *scsidp = sdp->device;
2671
2672                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2673                                    scsidp->host->host_no,
2674                                    scsidp->channel, scsidp->id,
2675                                    scsidp->lun,
2676                                    scsidp->host->hostt->emulated);
2677                 }
2678                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2679                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2680                 sg_proc_debug_helper(s, sdp);
2681         }
2682         read_unlock(&sdp->sfd_lock);
2683 skip:
2684         read_unlock_irqrestore(&sg_index_lock, iflags);
2685         return 0;
2686 }
2687
2688 #endif                          /* CONFIG_SCSI_PROC_FS */
2689
2690 module_init(init_sg);
2691 module_exit(exit_sg);