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