drivers/scsi/sg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  History:
   4  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   5  *           to allow user process control of SCSI devices.
   6  *  Development Sponsored by Killy Corp. NY NY
   7  *
   8  * Original driver (sg.c):
   9  *        Copyright (C) 1992 Lawrence Foard
  10  * Version 2 and 3 extensions to driver:
  11  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  12  */
  13
  14 static int sg_version_num = 30536;      /* 2 digits for each component */
  15 #define SG_VERSION_STR "3.5.36"
  16
  17 /*
  18  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  19  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  20  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  21  *        (otherwise the macros compile to empty statements).
  22  *
  23  */
  24 #include <linux/module.h>
  25
  26 #include <linux/fs.h>
  27 #include <linux/kernel.h>
  28 #include <linux/sched.h>
  29 #include <linux/string.h>
  30 #include <linux/mm.h>
  31 #include <linux/errno.h>
  32 #include <linux/mtio.h>
  33 #include <linux/ioctl.h>
  34 #include <linux/slab.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/init.h>
  37 #include <linux/poll.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/cdev.h>
  40 #include <linux/idr.h>
  41 #include <linux/seq_file.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/delay.h>
  44 #include <linux/blktrace_api.h>
  45 #include <linux/mutex.h>
  46 #include <linux/atomic.h>
  47 #include <linux/ratelimit.h>
  48 #include <linux/uio.h>
  49 #include <linux/cred.h> /* for sg_check_file_access() */
  50
  51 #include "scsi.h"
  52 #include <scsi/scsi_dbg.h>
  53 #include <scsi/scsi_host.h>
  54 #include <scsi/scsi_driver.h>
  55 #include <scsi/scsi_ioctl.h>
  56 #include <scsi/sg.h>
  57
  58 #include "scsi_logging.h"
  59
  60 #ifdef CONFIG_SCSI_PROC_FS
  61 #include <linux/proc_fs.h>
  62 static char *sg_version_date = "20140603";
  63
  64 static int sg_proc_init(void);
  65 #endif
  66
  67 #define SG_ALLOW_DIO_DEF 0
  68
  69 #define SG_MAX_DEVS 32768
  70
  71 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  72  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  73  * than 16 bytes are "variable length" whose length is a multiple of 4
  74  */
  75 #define SG_MAX_CDB_SIZE 252
  76
  77 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  78
  79 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  80 /* N.B. This variable is readable and writeable via
  81    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  82    of this size (or less if there is not enough memory) will be reserved
  83    for use by this file descriptor. [Deprecated usage: this variable is also
  84    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  85    the kernel (i.e. it is not a module).] */
  86 static int def_reserved_size = -1;      /* picks up init parameter */
  87 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  88
  89 static int scatter_elem_sz = SG_SCATTER_SZ;
  90 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  91
  92 #define SG_SECTOR_SZ 512
  93
  94 static int sg_add_device(struct device *, struct class_interface *);
  95 static void sg_remove_device(struct device *, struct class_interface *);
  96
  97 static DEFINE_IDR(sg_index_idr);
  98 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
  99                                                            file descriptor list for device */
 100
 101 static struct class_interface sg_interface = {
 102         .add_dev        = sg_add_device,
 103         .remove_dev     = sg_remove_device,
 104 };
 105
 106 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 107         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 108         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 109         unsigned bufflen;       /* Size of (aggregate) data buffer */
 110         struct page **pages;
 111         int page_order;
 112         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 113         unsigned char cmd_opcode; /* first byte of command */
 114 } Sg_scatter_hold;
 115
 116 struct sg_device;               /* forward declarations */
 117 struct sg_fd;
 118
 119 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 120         struct list_head entry; /* list entry */
 121         struct sg_fd *parentfp; /* NULL -> not in use */
 122         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 123         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 124         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 125         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 126         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 127         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 128         /* done protected by rq_list_lock */
 129         char done;              /* 0->before bh, 1->before read, 2->read */
 130         struct request *rq;
 131         struct bio *bio;
 132         struct execute_work ew;
 133 } Sg_request;
 134
 135 typedef struct sg_fd {          /* holds the state of a file descriptor */
 136         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 137         struct sg_device *parentdp;     /* owning device */
 138         wait_queue_head_t read_wait;    /* queue read until command done */
 139         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 140         struct mutex f_mutex;   /* protect against changes in this fd */
 141         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 142         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 143         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 144         struct list_head rq_list; /* head of request list */
 145         struct fasync_struct *async_qp; /* used by asynchronous notification */
 146         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 147         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 148         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 149         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 150         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 151         char mmap_called;       /* 0 -> mmap() never called on this fd */
 152         char res_in_use;        /* 1 -> 'reserve' array in use */
 153         struct kref f_ref;
 154         struct execute_work ew;
 155 } Sg_fd;
 156
 157 typedef struct sg_device { /* holds the state of each scsi generic device */
 158         struct scsi_device *device;
 159         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 160         struct mutex open_rel_lock;     /* held when in open() or release() */
 161         int sg_tablesize;       /* adapter's max scatter-gather table size */
 162         u32 index;              /* device index number */
 163         struct list_head sfds;
 164         rwlock_t sfd_lock;      /* protect access to sfd list */
 165         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 166         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 167         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 168         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 169         struct gendisk *disk;
 170         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 171         struct kref d_ref;
 172 } Sg_device;
 173
 174 /* tasklet or soft irq callback */
 175 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 176 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 177 static int sg_finish_rem_req(Sg_request * srp);
 178 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 179 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 180                            Sg_request * srp);
 181 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 182                         const char __user *buf, size_t count, int blocking,
 183                         int read_only, int sg_io_owned, Sg_request **o_srp);
 184 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 185                            unsigned char *cmnd, int timeout, int blocking);
 186 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 187 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 188 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 189 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 190 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 191 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 192 static void sg_remove_sfp(struct kref *);
 193 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 194 static Sg_request *sg_add_request(Sg_fd * sfp);
 195 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_device *sg_get_dev(int dev);
 197 static void sg_device_destroy(struct kref *kref);
 198
 199 #define SZ_SG_HEADER sizeof(struct sg_header)
 200 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 201 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 202 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 203
 204 #define sg_printk(prefix, sdp, fmt, a...) \
 205         sdev_prefix_printk(prefix, (sdp)->device,               \
 206                            (sdp)->disk->disk_name, fmt, ##a)
 207
 208 /*
 209  * The SCSI interfaces that use read() and write() as an asynchronous variant of
 210  * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
 211  * to trigger read() and write() calls from various contexts with elevated
 212  * privileges. This can lead to kernel memory corruption (e.g. if these
 213  * interfaces are called through splice()) and privilege escalation inside
 214  * userspace (e.g. if a process with access to such a device passes a file
 215  * descriptor to a SUID binary as stdin/stdout/stderr).
 216  *
 217  * This function provides protection for the legacy API by restricting the
 218  * calling context.
 219  */
 220 static int sg_check_file_access(struct file *filp, const char *caller)
 221 {
 222         if (filp->f_cred != current_real_cred()) {
 223                 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 224                         caller, task_tgid_vnr(current), current->comm);
 225                 return -EPERM;
 226         }
 227         if (uaccess_kernel()) {
 228                 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
 229                         caller, task_tgid_vnr(current), current->comm);
 230                 return -EACCES;
 231         }
 232         return 0;
 233 }
 234
 235 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 236 {
 237         struct sg_fd *sfp = filp->private_data;
 238
 239         if (sfp->parentdp->device->type == TYPE_SCANNER)
 240                 return 0;
 241
 242         return blk_verify_command(cmd, filp->f_mode);
 243 }
 244
 245 static int
 246 open_wait(Sg_device *sdp, int flags)
 247 {
 248         int retval = 0;
 249
 250         if (flags & O_EXCL) {
 251                 while (sdp->open_cnt > 0) {
 252                         mutex_unlock(&sdp->open_rel_lock);
 253                         retval = wait_event_interruptible(sdp->open_wait,
 254                                         (atomic_read(&sdp->detaching) ||
 255                                          !sdp->open_cnt));
 256                         mutex_lock(&sdp->open_rel_lock);
 257
 258                         if (retval) /* -ERESTARTSYS */
 259                                 return retval;
 260                         if (atomic_read(&sdp->detaching))
 261                                 return -ENODEV;
 262                 }
 263         } else {
 264                 while (sdp->exclude) {
 265                         mutex_unlock(&sdp->open_rel_lock);
 266                         retval = wait_event_interruptible(sdp->open_wait,
 267                                         (atomic_read(&sdp->detaching) ||
 268                                          !sdp->exclude));
 269                         mutex_lock(&sdp->open_rel_lock);
 270
 271                         if (retval) /* -ERESTARTSYS */
 272                                 return retval;
 273                         if (atomic_read(&sdp->detaching))
 274                                 return -ENODEV;
 275                 }
 276         }
 277
 278         return retval;
 279 }
 280
 281 /* Returns 0 on success, else a negated errno value */
 282 static int
 283 sg_open(struct inode *inode, struct file *filp)
 284 {
 285         int dev = iminor(inode);
 286         int flags = filp->f_flags;
 287         struct request_queue *q;
 288         Sg_device *sdp;
 289         Sg_fd *sfp;
 290         int retval;
 291
 292         nonseekable_open(inode, filp);
 293         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 294                 return -EPERM; /* Can't lock it with read only access */
 295         sdp = sg_get_dev(dev);
 296         if (IS_ERR(sdp))
 297                 return PTR_ERR(sdp);
 298
 299         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 300                                       "sg_open: flags=0x%x\n", flags));
 301
 302         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 303         /* Prevent the device driver from vanishing while we sleep */
 304         retval = scsi_device_get(sdp->device);
 305         if (retval)
 306                 goto sg_put;
 307
 308         retval = scsi_autopm_get_device(sdp->device);
 309         if (retval)
 310                 goto sdp_put;
 311
 312         /* scsi_block_when_processing_errors() may block so bypass
 313          * check if O_NONBLOCK. Permits SCSI commands to be issued
 314          * during error recovery. Tread carefully. */
 315         if (!((flags & O_NONBLOCK) ||
 316               scsi_block_when_processing_errors(sdp->device))) {
 317                 retval = -ENXIO;
 318                 /* we are in error recovery for this device */
 319                 goto error_out;
 320         }
 321
 322         mutex_lock(&sdp->open_rel_lock);
 323         if (flags & O_NONBLOCK) {
 324                 if (flags & O_EXCL) {
 325                         if (sdp->open_cnt > 0) {
 326                                 retval = -EBUSY;
 327                                 goto error_mutex_locked;
 328                         }
 329                 } else {
 330                         if (sdp->exclude) {
 331                                 retval = -EBUSY;
 332                                 goto error_mutex_locked;
 333                         }
 334                 }
 335         } else {
 336                 retval = open_wait(sdp, flags);
 337                 if (retval) /* -ERESTARTSYS or -ENODEV */
 338                         goto error_mutex_locked;
 339         }
 340
 341         /* N.B. at this point we are holding the open_rel_lock */
 342         if (flags & O_EXCL)
 343                 sdp->exclude = true;
 344
 345         if (sdp->open_cnt < 1) {  /* no existing opens */
 346                 sdp->sgdebug = 0;
 347                 q = sdp->device->request_queue;
 348                 sdp->sg_tablesize = queue_max_segments(q);
 349         }
 350         sfp = sg_add_sfp(sdp);
 351         if (IS_ERR(sfp)) {
 352                 retval = PTR_ERR(sfp);
 353                 goto out_undo;
 354         }
 355
 356         filp->private_data = sfp;
 357         sdp->open_cnt++;
 358         mutex_unlock(&sdp->open_rel_lock);
 359
 360         retval = 0;
 361 sg_put:
 362         kref_put(&sdp->d_ref, sg_device_destroy);
 363         return retval;
 364
 365 out_undo:
 366         if (flags & O_EXCL) {
 367                 sdp->exclude = false;   /* undo if error */
 368                 wake_up_interruptible(&sdp->open_wait);
 369         }
 370 error_mutex_locked:
 371         mutex_unlock(&sdp->open_rel_lock);
 372 error_out:
 373         scsi_autopm_put_device(sdp->device);
 374 sdp_put:
 375         scsi_device_put(sdp->device);
 376         goto sg_put;
 377 }
 378
 379 /* Release resources associated with a successful sg_open()
 380  * Returns 0 on success, else a negated errno value */
 381 static int
 382 sg_release(struct inode *inode, struct file *filp)
 383 {
 384         Sg_device *sdp;
 385         Sg_fd *sfp;
 386
 387         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 388                 return -ENXIO;
 389         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 390
 391         mutex_lock(&sdp->open_rel_lock);
 392         scsi_autopm_put_device(sdp->device);
 393         kref_put(&sfp->f_ref, sg_remove_sfp);
 394         sdp->open_cnt--;
 395
 396         /* possibly many open()s waiting on exlude clearing, start many;
 397          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 398         if (sdp->exclude) {
 399                 sdp->exclude = false;
 400                 wake_up_interruptible_all(&sdp->open_wait);
 401         } else if (0 == sdp->open_cnt) {
 402                 wake_up_interruptible(&sdp->open_wait);
 403         }
 404         mutex_unlock(&sdp->open_rel_lock);
 405         return 0;
 406 }
 407
 408 static ssize_t
 409 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 410 {
 411         Sg_device *sdp;
 412         Sg_fd *sfp;
 413         Sg_request *srp;
 414         int req_pack_id = -1;
 415         sg_io_hdr_t *hp;
 416         struct sg_header *old_hdr = NULL;
 417         int retval = 0;
 418
 419         /*
 420          * This could cause a response to be stranded. Close the associated
 421          * file descriptor to free up any resources being held.
 422          */
 423         retval = sg_check_file_access(filp, __func__);
 424         if (retval)
 425                 return retval;
 426
 427         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 428                 return -ENXIO;
 429         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 430                                       "sg_read: count=%d\n", (int) count));
 431
 432         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 433                 old_hdr = memdup_user(buf, SZ_SG_HEADER);
 434                 if (IS_ERR(old_hdr))
 435                         return PTR_ERR(old_hdr);
 436                 if (old_hdr->reply_len < 0) {
 437                         if (count >= SZ_SG_IO_HDR) {
 438                                 sg_io_hdr_t __user *p = (void __user *)buf;
 439                                 if (get_user(req_pack_id, &p->pack_id)) {
 440                                         retval = -EFAULT;
 441                                         goto free_old_hdr;
 442                                 }
 443                         }
 444                 } else
 445                         req_pack_id = old_hdr->pack_id;
 446         }
 447         srp = sg_get_rq_mark(sfp, req_pack_id);
 448         if (!srp) {             /* now wait on packet to arrive */
 449                 if (atomic_read(&sdp->detaching)) {
 450                         retval = -ENODEV;
 451                         goto free_old_hdr;
 452                 }
 453                 if (filp->f_flags & O_NONBLOCK) {
 454                         retval = -EAGAIN;
 455                         goto free_old_hdr;
 456                 }
 457                 retval = wait_event_interruptible(sfp->read_wait,
 458                         (atomic_read(&sdp->detaching) ||
 459                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 460                 if (atomic_read(&sdp->detaching)) {
 461                         retval = -ENODEV;
 462                         goto free_old_hdr;
 463                 }
 464                 if (retval) {
 465                         /* -ERESTARTSYS as signal hit process */
 466                         goto free_old_hdr;
 467                 }
 468         }
 469         if (srp->header.interface_id != '\0') {
 470                 retval = sg_new_read(sfp, buf, count, srp);
 471                 goto free_old_hdr;
 472         }
 473
 474         hp = &srp->header;
 475         if (old_hdr == NULL) {
 476                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 477                 if (! old_hdr) {
 478                         retval = -ENOMEM;
 479                         goto free_old_hdr;
 480                 }
 481         }
 482         memset(old_hdr, 0, SZ_SG_HEADER);
 483         old_hdr->reply_len = (int) hp->timeout;
 484         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 485         old_hdr->pack_id = hp->pack_id;
 486         old_hdr->twelve_byte =
 487             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 488         old_hdr->target_status = hp->masked_status;
 489         old_hdr->host_status = hp->host_status;
 490         old_hdr->driver_status = hp->driver_status;
 491         if ((CHECK_CONDITION & hp->masked_status) ||
 492             (DRIVER_SENSE & hp->driver_status))
 493                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 494                        sizeof (old_hdr->sense_buffer));
 495         switch (hp->host_status) {
 496         /* This setup of 'result' is for backward compatibility and is best
 497            ignored by the user who should use target, host + driver status */
 498         case DID_OK:
 499         case DID_PASSTHROUGH:
 500         case DID_SOFT_ERROR:
 501                 old_hdr->result = 0;
 502                 break;
 503         case DID_NO_CONNECT:
 504         case DID_BUS_BUSY:
 505         case DID_TIME_OUT:
 506                 old_hdr->result = EBUSY;
 507                 break;
 508         case DID_BAD_TARGET:
 509         case DID_ABORT:
 510         case DID_PARITY:
 511         case DID_RESET:
 512         case DID_BAD_INTR:
 513                 old_hdr->result = EIO;
 514                 break;
 515         case DID_ERROR:
 516                 old_hdr->result = (srp->sense_b[0] == 0 &&
 517                                   hp->masked_status == GOOD) ? 0 : EIO;
 518                 break;
 519         default:
 520                 old_hdr->result = EIO;
 521                 break;
 522         }
 523
 524         /* Now copy the result back to the user buffer.  */
 525         if (count >= SZ_SG_HEADER) {
 526                 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 527                         retval = -EFAULT;
 528                         goto free_old_hdr;
 529                 }
 530                 buf += SZ_SG_HEADER;
 531                 if (count > old_hdr->reply_len)
 532                         count = old_hdr->reply_len;
 533                 if (count > SZ_SG_HEADER) {
 534                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 535                                 retval = -EFAULT;
 536                                 goto free_old_hdr;
 537                         }
 538                 }
 539         } else
 540                 count = (old_hdr->result == 0) ? 0 : -EIO;
 541         sg_finish_rem_req(srp);
 542         sg_remove_request(sfp, srp);
 543         retval = count;
 544 free_old_hdr:
 545         kfree(old_hdr);
 546         return retval;
 547 }
 548
 549 static ssize_t
 550 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 551 {
 552         sg_io_hdr_t *hp = &srp->header;
 553         int err = 0, err2;
 554         int len;
 555
 556         if (count < SZ_SG_IO_HDR) {
 557                 err = -EINVAL;
 558                 goto err_out;
 559         }
 560         hp->sb_len_wr = 0;
 561         if ((hp->mx_sb_len > 0) && hp->sbp) {
 562                 if ((CHECK_CONDITION & hp->masked_status) ||
 563                     (DRIVER_SENSE & hp->driver_status)) {
 564                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 565                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 566                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 567                         len = (len > sb_len) ? sb_len : len;
 568                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 569                                 err = -EFAULT;
 570                                 goto err_out;
 571                         }
 572                         hp->sb_len_wr = len;
 573                 }
 574         }
 575         if (hp->masked_status || hp->host_status || hp->driver_status)
 576                 hp->info |= SG_INFO_CHECK;
 577         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 578                 err = -EFAULT;
 579                 goto err_out;
 580         }
 581 err_out:
 582         err2 = sg_finish_rem_req(srp);
 583         sg_remove_request(sfp, srp);
 584         return err ? : err2 ? : count;
 585 }
 586
 587 static ssize_t
 588 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 589 {
 590         int mxsize, cmd_size, k;
 591         int input_size, blocking;
 592         unsigned char opcode;
 593         Sg_device *sdp;
 594         Sg_fd *sfp;
 595         Sg_request *srp;
 596         struct sg_header old_hdr;
 597         sg_io_hdr_t *hp;
 598         unsigned char cmnd[SG_MAX_CDB_SIZE];
 599         int retval;
 600
 601         retval = sg_check_file_access(filp, __func__);
 602         if (retval)
 603                 return retval;
 604
 605         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 606                 return -ENXIO;
 607         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 608                                       "sg_write: count=%d\n", (int) count));
 609         if (atomic_read(&sdp->detaching))
 610                 return -ENODEV;
 611         if (!((filp->f_flags & O_NONBLOCK) ||
 612               scsi_block_when_processing_errors(sdp->device)))
 613                 return -ENXIO;
 614
 615         if (count < SZ_SG_HEADER)
 616                 return -EIO;
 617         if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 618                 return -EFAULT;
 619         blocking = !(filp->f_flags & O_NONBLOCK);
 620         if (old_hdr.reply_len < 0)
 621                 return sg_new_write(sfp, filp, buf, count,
 622                                     blocking, 0, 0, NULL);
 623         if (count < (SZ_SG_HEADER + 6))
 624                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 625
 626         buf += SZ_SG_HEADER;
 627         if (get_user(opcode, buf))
 628                 return -EFAULT;
 629
 630         if (!(srp = sg_add_request(sfp))) {
 631                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 632                                               "sg_write: queue full\n"));
 633                 return -EDOM;
 634         }
 635         mutex_lock(&sfp->f_mutex);
 636         if (sfp->next_cmd_len > 0) {
 637                 cmd_size = sfp->next_cmd_len;
 638                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 639         } else {
 640                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 641                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 642                         cmd_size = 12;
 643         }
 644         mutex_unlock(&sfp->f_mutex);
 645         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 646                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 647 /* Determine buffer size.  */
 648         input_size = count - cmd_size;
 649         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 650         mxsize -= SZ_SG_HEADER;
 651         input_size -= SZ_SG_HEADER;
 652         if (input_size < 0) {
 653                 sg_remove_request(sfp, srp);
 654                 return -EIO;    /* User did not pass enough bytes for this command. */
 655         }
 656         hp = &srp->header;
 657         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 658         hp->cmd_len = (unsigned char) cmd_size;
 659         hp->iovec_count = 0;
 660         hp->mx_sb_len = 0;
 661         if (input_size > 0)
 662                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 663                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 664         else
 665                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 666         hp->dxfer_len = mxsize;
 667         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 668             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 669                 hp->dxferp = (char __user *)buf + cmd_size;
 670         else
 671                 hp->dxferp = NULL;
 672         hp->sbp = NULL;
 673         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 674         hp->flags = input_size; /* structure abuse ... */
 675         hp->pack_id = old_hdr.pack_id;
 676         hp->usr_ptr = NULL;
 677         if (copy_from_user(cmnd, buf, cmd_size))
 678                 return -EFAULT;
 679         /*
 680          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 681          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 682          * is a non-zero input_size, so emit a warning.
 683          */
 684         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 685                 printk_ratelimited(KERN_WARNING
 686                                    "sg_write: data in/out %d/%d bytes "
 687                                    "for SCSI command 0x%x-- guessing "
 688                                    "data in;\n   program %s not setting "
 689                                    "count and/or reply_len properly\n",
 690                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 691                                    input_size, (unsigned int) cmnd[0],
 692                                    current->comm);
 693         }
 694         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 695         return (k < 0) ? k : count;
 696 }
 697
 698 static ssize_t
 699 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 700                  size_t count, int blocking, int read_only, int sg_io_owned,
 701                  Sg_request **o_srp)
 702 {
 703         int k;
 704         Sg_request *srp;
 705         sg_io_hdr_t *hp;
 706         unsigned char cmnd[SG_MAX_CDB_SIZE];
 707         int timeout;
 708         unsigned long ul_timeout;
 709
 710         if (count < SZ_SG_IO_HDR)
 711                 return -EINVAL;
 712
 713         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 714         if (!(srp = sg_add_request(sfp))) {
 715                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 716                                               "sg_new_write: queue full\n"));
 717                 return -EDOM;
 718         }
 719         srp->sg_io_owned = sg_io_owned;
 720         hp = &srp->header;
 721         if (copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 722                 sg_remove_request(sfp, srp);
 723                 return -EFAULT;
 724         }
 725         if (hp->interface_id != 'S') {
 726                 sg_remove_request(sfp, srp);
 727                 return -ENOSYS;
 728         }
 729         if (hp->flags & SG_FLAG_MMAP_IO) {
 730                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 731                         sg_remove_request(sfp, srp);
 732                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 733                 }
 734                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 735                         sg_remove_request(sfp, srp);
 736                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 737                 }
 738                 if (sfp->res_in_use) {
 739                         sg_remove_request(sfp, srp);
 740                         return -EBUSY;  /* reserve buffer already being used */
 741                 }
 742         }
 743         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 744         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 745         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 746                 sg_remove_request(sfp, srp);
 747                 return -EMSGSIZE;
 748         }
 749         if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 750                 sg_remove_request(sfp, srp);
 751                 return -EFAULT;
 752         }
 753         if (read_only && sg_allow_access(file, cmnd)) {
 754                 sg_remove_request(sfp, srp);
 755                 return -EPERM;
 756         }
 757         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 758         if (k < 0)
 759                 return k;
 760         if (o_srp)
 761                 *o_srp = srp;
 762         return count;
 763 }
 764
 765 static int
 766 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 767                 unsigned char *cmnd, int timeout, int blocking)
 768 {
 769         int k, at_head;
 770         Sg_device *sdp = sfp->parentdp;
 771         sg_io_hdr_t *hp = &srp->header;
 772
 773         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 774         hp->status = 0;
 775         hp->masked_status = 0;
 776         hp->msg_status = 0;
 777         hp->info = 0;
 778         hp->host_status = 0;
 779         hp->driver_status = 0;
 780         hp->resid = 0;
 781         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 782                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 783                         (int) cmnd[0], (int) hp->cmd_len));
 784
 785         if (hp->dxfer_len >= SZ_256M)
 786                 return -EINVAL;
 787
 788         k = sg_start_req(srp, cmnd);
 789         if (k) {
 790                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 791                         "sg_common_write: start_req err=%d\n", k));
 792                 sg_finish_rem_req(srp);
 793                 sg_remove_request(sfp, srp);
 794                 return k;       /* probably out of space --> ENOMEM */
 795         }
 796         if (atomic_read(&sdp->detaching)) {
 797                 if (srp->bio) {
 798                         scsi_req_free_cmd(scsi_req(srp->rq));
 799                         blk_put_request(srp->rq);
 800                         srp->rq = NULL;
 801                 }
 802
 803                 sg_finish_rem_req(srp);
 804                 sg_remove_request(sfp, srp);
 805                 return -ENODEV;
 806         }
 807
 808         hp->duration = jiffies_to_msecs(jiffies);
 809         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 810             (SG_FLAG_Q_AT_TAIL & hp->flags))
 811                 at_head = 0;
 812         else
 813                 at_head = 1;
 814
 815         srp->rq->timeout = timeout;
 816         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 817         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 818                               srp->rq, at_head, sg_rq_end_io);
 819         return 0;
 820 }
 821
 822 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 823 {
 824         unsigned long flags;
 825         int ret;
 826
 827         read_lock_irqsave(&sfp->rq_list_lock, flags);
 828         ret = srp->done;
 829         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 830         return ret;
 831 }
 832
 833 static int max_sectors_bytes(struct request_queue *q)
 834 {
 835         unsigned int max_sectors = queue_max_sectors(q);
 836
 837         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 838
 839         return max_sectors << 9;
 840 }
 841
 842 static void
 843 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 844 {
 845         Sg_request *srp;
 846         int val;
 847         unsigned int ms;
 848
 849         val = 0;
 850         list_for_each_entry(srp, &sfp->rq_list, entry) {
 851                 if (val >= SG_MAX_QUEUE)
 852                         break;
 853                 rinfo[val].req_state = srp->done + 1;
 854                 rinfo[val].problem =
 855                         srp->header.masked_status &
 856                         srp->header.host_status &
 857                         srp->header.driver_status;
 858                 if (srp->done)
 859                         rinfo[val].duration =
 860                                 srp->header.duration;
 861                 else {
 862                         ms = jiffies_to_msecs(jiffies);
 863                         rinfo[val].duration =
 864                                 (ms > srp->header.duration) ?
 865                                 (ms - srp->header.duration) : 0;
 866                 }
 867                 rinfo[val].orphan = srp->orphan;
 868                 rinfo[val].sg_io_owned = srp->sg_io_owned;
 869                 rinfo[val].pack_id = srp->header.pack_id;
 870                 rinfo[val].usr_ptr = srp->header.usr_ptr;
 871                 val++;
 872         }
 873 }
 874
 875 static long
 876 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 877 {
 878         void __user *p = (void __user *)arg;
 879         int __user *ip = p;
 880         int result, val, read_only;
 881         Sg_device *sdp;
 882         Sg_fd *sfp;
 883         Sg_request *srp;
 884         unsigned long iflags;
 885
 886         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 887                 return -ENXIO;
 888
 889         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 890                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 891         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 892
 893         switch (cmd_in) {
 894         case SG_IO:
 895                 if (atomic_read(&sdp->detaching))
 896                         return -ENODEV;
 897                 if (!scsi_block_when_processing_errors(sdp->device))
 898                         return -ENXIO;
 899                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 900                                  1, read_only, 1, &srp);
 901                 if (result < 0)
 902                         return result;
 903                 result = wait_event_interruptible(sfp->read_wait,
 904                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 905                 if (atomic_read(&sdp->detaching))
 906                         return -ENODEV;
 907                 write_lock_irq(&sfp->rq_list_lock);
 908                 if (srp->done) {
 909                         srp->done = 2;
 910                         write_unlock_irq(&sfp->rq_list_lock);
 911                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 912                         return (result < 0) ? result : 0;
 913                 }
 914                 srp->orphan = 1;
 915                 write_unlock_irq(&sfp->rq_list_lock);
 916                 return result;  /* -ERESTARTSYS because signal hit process */
 917         case SG_SET_TIMEOUT:
 918                 result = get_user(val, ip);
 919                 if (result)
 920                         return result;
 921                 if (val < 0)
 922                         return -EIO;
 923                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 924                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 925                                     INT_MAX);
 926                 sfp->timeout_user = val;
 927                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 928
 929                 return 0;
 930         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 931                                 /* strange ..., for backward compatibility */
 932                 return sfp->timeout_user;
 933         case SG_SET_FORCE_LOW_DMA:
 934                 /*
 935                  * N.B. This ioctl never worked properly, but failed to
 936                  * return an error value. So returning '0' to keep compability
 937                  * with legacy applications.
 938                  */
 939                 return 0;
 940         case SG_GET_LOW_DMA:
 941                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 942         case SG_GET_SCSI_ID:
 943                 {
 944                         sg_scsi_id_t v;
 945
 946                         if (atomic_read(&sdp->detaching))
 947                                 return -ENODEV;
 948                         memset(&v, 0, sizeof(v));
 949                         v.host_no = sdp->device->host->host_no;
 950                         v.channel = sdp->device->channel;
 951                         v.scsi_id = sdp->device->id;
 952                         v.lun = sdp->device->lun;
 953                         v.scsi_type = sdp->device->type;
 954                         v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
 955                         v.d_queue_depth = sdp->device->queue_depth;
 956                         if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
 957                                 return -EFAULT;
 958                         return 0;
 959                 }
 960         case SG_SET_FORCE_PACK_ID:
 961                 result = get_user(val, ip);
 962                 if (result)
 963                         return result;
 964                 sfp->force_packid = val ? 1 : 0;
 965                 return 0;
 966         case SG_GET_PACK_ID:
 967                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 968                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 969                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 970                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 971                                                        iflags);
 972                                 return put_user(srp->header.pack_id, ip);
 973                         }
 974                 }
 975                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 976                 return put_user(-1, ip);
 977         case SG_GET_NUM_WAITING:
 978                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 979                 val = 0;
 980                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 981                         if ((1 == srp->done) && (!srp->sg_io_owned))
 982                                 ++val;
 983                 }
 984                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 985                 return put_user(val, ip);
 986         case SG_GET_SG_TABLESIZE:
 987                 return put_user(sdp->sg_tablesize, ip);
 988         case SG_SET_RESERVED_SIZE:
 989                 result = get_user(val, ip);
 990                 if (result)
 991                         return result;
 992                 if (val < 0)
 993                         return -EINVAL;
 994                 val = min_t(int, val,
 995                             max_sectors_bytes(sdp->device->request_queue));
 996                 mutex_lock(&sfp->f_mutex);
 997                 if (val != sfp->reserve.bufflen) {
 998                         if (sfp->mmap_called ||
 999                             sfp->res_in_use) {
1000                                 mutex_unlock(&sfp->f_mutex);
1001                                 return -EBUSY;
1002                         }
1003
1004                         sg_remove_scat(sfp, &sfp->reserve);
1005                         sg_build_reserve(sfp, val);
1006                 }
1007                 mutex_unlock(&sfp->f_mutex);
1008                 return 0;
1009         case SG_GET_RESERVED_SIZE:
1010                 val = min_t(int, sfp->reserve.bufflen,
1011                             max_sectors_bytes(sdp->device->request_queue));
1012                 return put_user(val, ip);
1013         case SG_SET_COMMAND_Q:
1014                 result = get_user(val, ip);
1015                 if (result)
1016                         return result;
1017                 sfp->cmd_q = val ? 1 : 0;
1018                 return 0;
1019         case SG_GET_COMMAND_Q:
1020                 return put_user((int) sfp->cmd_q, ip);
1021         case SG_SET_KEEP_ORPHAN:
1022                 result = get_user(val, ip);
1023                 if (result)
1024                         return result;
1025                 sfp->keep_orphan = val;
1026                 return 0;
1027         case SG_GET_KEEP_ORPHAN:
1028                 return put_user((int) sfp->keep_orphan, ip);
1029         case SG_NEXT_CMD_LEN:
1030                 result = get_user(val, ip);
1031                 if (result)
1032                         return result;
1033                 if (val > SG_MAX_CDB_SIZE)
1034                         return -ENOMEM;
1035                 sfp->next_cmd_len = (val > 0) ? val : 0;
1036                 return 0;
1037         case SG_GET_VERSION_NUM:
1038                 return put_user(sg_version_num, ip);
1039         case SG_GET_ACCESS_COUNT:
1040                 /* faked - we don't have a real access count anymore */
1041                 val = (sdp->device ? 1 : 0);
1042                 return put_user(val, ip);
1043         case SG_GET_REQUEST_TABLE:
1044                 {
1045                         sg_req_info_t *rinfo;
1046
1047                         rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1048                                         GFP_KERNEL);
1049                         if (!rinfo)
1050                                 return -ENOMEM;
1051                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1052                         sg_fill_request_table(sfp, rinfo);
1053                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1054                         result = copy_to_user(p, rinfo,
1055                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1056                         result = result ? -EFAULT : 0;
1057                         kfree(rinfo);
1058                         return result;
1059                 }
1060         case SG_EMULATED_HOST:
1061                 if (atomic_read(&sdp->detaching))
1062                         return -ENODEV;
1063                 return put_user(sdp->device->host->hostt->emulated, ip);
1064         case SCSI_IOCTL_SEND_COMMAND:
1065                 if (atomic_read(&sdp->detaching))
1066                         return -ENODEV;
1067                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1068         case SG_SET_DEBUG:
1069                 result = get_user(val, ip);
1070                 if (result)
1071                         return result;
1072                 sdp->sgdebug = (char) val;
1073                 return 0;
1074         case BLKSECTGET:
1075                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1076                                 ip);
1077         case BLKTRACESETUP:
1078                 return blk_trace_setup(sdp->device->request_queue,
1079                                        sdp->disk->disk_name,
1080                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1081                                        NULL, p);
1082         case BLKTRACESTART:
1083                 return blk_trace_startstop(sdp->device->request_queue, 1);
1084         case BLKTRACESTOP:
1085                 return blk_trace_startstop(sdp->device->request_queue, 0);
1086         case BLKTRACETEARDOWN:
1087                 return blk_trace_remove(sdp->device->request_queue);
1088         case SCSI_IOCTL_GET_IDLUN:
1089         case SCSI_IOCTL_GET_BUS_NUMBER:
1090         case SCSI_IOCTL_PROBE_HOST:
1091         case SG_GET_TRANSFORM:
1092         case SG_SCSI_RESET:
1093                 if (atomic_read(&sdp->detaching))
1094                         return -ENODEV;
1095                 break;
1096         default:
1097                 if (read_only)
1098                         return -EPERM;  /* don't know so take safe approach */
1099                 break;
1100         }
1101
1102         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1103                         cmd_in, filp->f_flags & O_NDELAY);
1104         if (result)
1105                 return result;
1106         return scsi_ioctl(sdp->device, cmd_in, p);
1107 }
1108
1109 #ifdef CONFIG_COMPAT
1110 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1111 {
1112         Sg_device *sdp;
1113         Sg_fd *sfp;
1114         struct scsi_device *sdev;
1115
1116         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1117                 return -ENXIO;
1118
1119         sdev = sdp->device;
1120         if (sdev->host->hostt->compat_ioctl) {
1121                 int ret;
1122
1123                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1124
1125                 return ret;
1126         }
1127
1128         return -ENOIOCTLCMD;
1129 }
1130 #endif
1131
1132 static __poll_t
1133 sg_poll(struct file *filp, poll_table * wait)
1134 {
1135         __poll_t res = 0;
1136         Sg_device *sdp;
1137         Sg_fd *sfp;
1138         Sg_request *srp;
1139         int count = 0;
1140         unsigned long iflags;
1141
1142         sfp = filp->private_data;
1143         if (!sfp)
1144                 return EPOLLERR;
1145         sdp = sfp->parentdp;
1146         if (!sdp)
1147                 return EPOLLERR;
1148         poll_wait(filp, &sfp->read_wait, wait);
1149         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1150         list_for_each_entry(srp, &sfp->rq_list, entry) {
1151                 /* if any read waiting, flag it */
1152                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1153                         res = EPOLLIN | EPOLLRDNORM;
1154                 ++count;
1155         }
1156         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1157
1158         if (atomic_read(&sdp->detaching))
1159                 res |= EPOLLHUP;
1160         else if (!sfp->cmd_q) {
1161                 if (0 == count)
1162                         res |= EPOLLOUT | EPOLLWRNORM;
1163         } else if (count < SG_MAX_QUEUE)
1164                 res |= EPOLLOUT | EPOLLWRNORM;
1165         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1166                                       "sg_poll: res=0x%x\n", (__force u32) res));
1167         return res;
1168 }
1169
1170 static int
1171 sg_fasync(int fd, struct file *filp, int mode)
1172 {
1173         Sg_device *sdp;
1174         Sg_fd *sfp;
1175
1176         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1177                 return -ENXIO;
1178         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1179                                       "sg_fasync: mode=%d\n", mode));
1180
1181         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1182 }
1183
1184 static vm_fault_t
1185 sg_vma_fault(struct vm_fault *vmf)
1186 {
1187         struct vm_area_struct *vma = vmf->vma;
1188         Sg_fd *sfp;
1189         unsigned long offset, len, sa;
1190         Sg_scatter_hold *rsv_schp;
1191         int k, length;
1192
1193         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1194                 return VM_FAULT_SIGBUS;
1195         rsv_schp = &sfp->reserve;
1196         offset = vmf->pgoff << PAGE_SHIFT;
1197         if (offset >= rsv_schp->bufflen)
1198                 return VM_FAULT_SIGBUS;
1199         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1200                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1201                                       offset, rsv_schp->k_use_sg));
1202         sa = vma->vm_start;
1203         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1204         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1205                 len = vma->vm_end - sa;
1206                 len = (len < length) ? len : length;
1207                 if (offset < len) {
1208                         struct page *page = nth_page(rsv_schp->pages[k],
1209                                                      offset >> PAGE_SHIFT);
1210                         get_page(page); /* increment page count */
1211                         vmf->page = page;
1212                         return 0; /* success */
1213                 }
1214                 sa += len;
1215                 offset -= len;
1216         }
1217
1218         return VM_FAULT_SIGBUS;
1219 }
1220
1221 static const struct vm_operations_struct sg_mmap_vm_ops = {
1222         .fault = sg_vma_fault,
1223 };
1224
1225 static int
1226 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1227 {
1228         Sg_fd *sfp;
1229         unsigned long req_sz, len, sa;
1230         Sg_scatter_hold *rsv_schp;
1231         int k, length;
1232         int ret = 0;
1233
1234         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1235                 return -ENXIO;
1236         req_sz = vma->vm_end - vma->vm_start;
1237         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1238                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1239                                       (void *) vma->vm_start, (int) req_sz));
1240         if (vma->vm_pgoff)
1241                 return -EINVAL; /* want no offset */
1242         rsv_schp = &sfp->reserve;
1243         mutex_lock(&sfp->f_mutex);
1244         if (req_sz > rsv_schp->bufflen) {
1245                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1246                 goto out;
1247         }
1248
1249         sa = vma->vm_start;
1250         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1251         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1252                 len = vma->vm_end - sa;
1253                 len = (len < length) ? len : length;
1254                 sa += len;
1255         }
1256
1257         sfp->mmap_called = 1;
1258         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1259         vma->vm_private_data = sfp;
1260         vma->vm_ops = &sg_mmap_vm_ops;
1261 out:
1262         mutex_unlock(&sfp->f_mutex);
1263         return ret;
1264 }
1265
1266 static void
1267 sg_rq_end_io_usercontext(struct work_struct *work)
1268 {
1269         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1270         struct sg_fd *sfp = srp->parentfp;
1271
1272         sg_finish_rem_req(srp);
1273         sg_remove_request(sfp, srp);
1274         kref_put(&sfp->f_ref, sg_remove_sfp);
1275 }
1276
1277 /*
1278  * This function is a "bottom half" handler that is called by the mid
1279  * level when a command is completed (or has failed).
1280  */
1281 static void
1282 sg_rq_end_io(struct request *rq, blk_status_t status)
1283 {
1284         struct sg_request *srp = rq->end_io_data;
1285         struct scsi_request *req = scsi_req(rq);
1286         Sg_device *sdp;
1287         Sg_fd *sfp;
1288         unsigned long iflags;
1289         unsigned int ms;
1290         char *sense;
1291         int result, resid, done = 1;
1292
1293         if (WARN_ON(srp->done != 0))
1294                 return;
1295
1296         sfp = srp->parentfp;
1297         if (WARN_ON(sfp == NULL))
1298                 return;
1299
1300         sdp = sfp->parentdp;
1301         if (unlikely(atomic_read(&sdp->detaching)))
1302                 pr_info("%s: device detaching\n", __func__);
1303
1304         sense = req->sense;
1305         result = req->result;
1306         resid = req->resid_len;
1307
1308         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1309                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1310                                       srp->header.pack_id, result));
1311         srp->header.resid = resid;
1312         ms = jiffies_to_msecs(jiffies);
1313         srp->header.duration = (ms > srp->header.duration) ?
1314                                 (ms - srp->header.duration) : 0;
1315         if (0 != result) {
1316                 struct scsi_sense_hdr sshdr;
1317
1318                 srp->header.status = 0xff & result;
1319                 srp->header.masked_status = status_byte(result);
1320                 srp->header.msg_status = msg_byte(result);
1321                 srp->header.host_status = host_byte(result);
1322                 srp->header.driver_status = driver_byte(result);
1323                 if ((sdp->sgdebug > 0) &&
1324                     ((CHECK_CONDITION == srp->header.masked_status) ||
1325                      (COMMAND_TERMINATED == srp->header.masked_status)))
1326                         __scsi_print_sense(sdp->device, __func__, sense,
1327                                            SCSI_SENSE_BUFFERSIZE);
1328
1329                 /* Following if statement is a patch supplied by Eric Youngdale */
1330                 if (driver_byte(result) != 0
1331                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1332                     && !scsi_sense_is_deferred(&sshdr)
1333                     && sshdr.sense_key == UNIT_ATTENTION
1334                     && sdp->device->removable) {
1335                         /* Detected possible disc change. Set the bit - this */
1336                         /* may be used if there are filesystems using this device */
1337                         sdp->device->changed = 1;
1338                 }
1339         }
1340
1341         if (req->sense_len)
1342                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1343
1344         /* Rely on write phase to clean out srp status values, so no "else" */
1345
1346         /*
1347          * Free the request as soon as it is complete so that its resources
1348          * can be reused without waiting for userspace to read() the
1349          * result.  But keep the associated bio (if any) around until
1350          * blk_rq_unmap_user() can be called from user context.
1351          */
1352         srp->rq = NULL;
1353         scsi_req_free_cmd(scsi_req(rq));
1354         blk_put_request(rq);
1355
1356         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1357         if (unlikely(srp->orphan)) {
1358                 if (sfp->keep_orphan)
1359                         srp->sg_io_owned = 0;
1360                 else
1361                         done = 0;
1362         }
1363         srp->done = done;
1364         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1365
1366         if (likely(done)) {
1367                 /* Now wake up any sg_read() that is waiting for this
1368                  * packet.
1369                  */
1370                 wake_up_interruptible(&sfp->read_wait);
1371                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1372                 kref_put(&sfp->f_ref, sg_remove_sfp);
1373         } else {
1374                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1375                 schedule_work(&srp->ew.work);
1376         }
1377 }
1378
1379 static const struct file_operations sg_fops = {
1380         .owner = THIS_MODULE,
1381         .read = sg_read,
1382         .write = sg_write,
1383         .poll = sg_poll,
1384         .unlocked_ioctl = sg_ioctl,
1385 #ifdef CONFIG_COMPAT
1386         .compat_ioctl = sg_compat_ioctl,
1387 #endif
1388         .open = sg_open,
1389         .mmap = sg_mmap,
1390         .release = sg_release,
1391         .fasync = sg_fasync,
1392         .llseek = no_llseek,
1393 };
1394
1395 static struct class *sg_sysfs_class;
1396
1397 static int sg_sysfs_valid = 0;
1398
1399 static Sg_device *
1400 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1401 {
1402         struct request_queue *q = scsidp->request_queue;
1403         Sg_device *sdp;
1404         unsigned long iflags;
1405         int error;
1406         u32 k;
1407
1408         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1409         if (!sdp) {
1410                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1411                             "failure\n", __func__);
1412                 return ERR_PTR(-ENOMEM);
1413         }
1414
1415         idr_preload(GFP_KERNEL);
1416         write_lock_irqsave(&sg_index_lock, iflags);
1417
1418         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1419         if (error < 0) {
1420                 if (error == -ENOSPC) {
1421                         sdev_printk(KERN_WARNING, scsidp,
1422                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1423                                     scsidp->type, SG_MAX_DEVS - 1);
1424                         error = -ENODEV;
1425                 } else {
1426                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1427                                     "allocation Sg_device failure: %d\n",
1428                                     __func__, error);
1429                 }
1430                 goto out_unlock;
1431         }
1432         k = error;
1433
1434         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1435                                         "sg_alloc: dev=%d \n", k));
1436         sprintf(disk->disk_name, "sg%d", k);
1437         disk->first_minor = k;
1438         sdp->disk = disk;
1439         sdp->device = scsidp;
1440         mutex_init(&sdp->open_rel_lock);
1441         INIT_LIST_HEAD(&sdp->sfds);
1442         init_waitqueue_head(&sdp->open_wait);
1443         atomic_set(&sdp->detaching, 0);
1444         rwlock_init(&sdp->sfd_lock);
1445         sdp->sg_tablesize = queue_max_segments(q);
1446         sdp->index = k;
1447         kref_init(&sdp->d_ref);
1448         error = 0;
1449
1450 out_unlock:
1451         write_unlock_irqrestore(&sg_index_lock, iflags);
1452         idr_preload_end();
1453
1454         if (error) {
1455                 kfree(sdp);
1456                 return ERR_PTR(error);
1457         }
1458         return sdp;
1459 }
1460
1461 static int
1462 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1463 {
1464         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1465         struct gendisk *disk;
1466         Sg_device *sdp = NULL;
1467         struct cdev * cdev = NULL;
1468         int error;
1469         unsigned long iflags;
1470
1471         disk = alloc_disk(1);
1472         if (!disk) {
1473                 pr_warn("%s: alloc_disk failed\n", __func__);
1474                 return -ENOMEM;
1475         }
1476         disk->major = SCSI_GENERIC_MAJOR;
1477
1478         error = -ENOMEM;
1479         cdev = cdev_alloc();
1480         if (!cdev) {
1481                 pr_warn("%s: cdev_alloc failed\n", __func__);
1482                 goto out;
1483         }
1484         cdev->owner = THIS_MODULE;
1485         cdev->ops = &sg_fops;
1486
1487         sdp = sg_alloc(disk, scsidp);
1488         if (IS_ERR(sdp)) {
1489                 pr_warn("%s: sg_alloc failed\n", __func__);
1490                 error = PTR_ERR(sdp);
1491                 goto out;
1492         }
1493
1494         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1495         if (error)
1496                 goto cdev_add_err;
1497
1498         sdp->cdev = cdev;
1499         if (sg_sysfs_valid) {
1500                 struct device *sg_class_member;
1501
1502                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1503                                                 MKDEV(SCSI_GENERIC_MAJOR,
1504                                                       sdp->index),
1505                                                 sdp, "%s", disk->disk_name);
1506                 if (IS_ERR(sg_class_member)) {
1507                         pr_err("%s: device_create failed\n", __func__);
1508                         error = PTR_ERR(sg_class_member);
1509                         goto cdev_add_err;
1510                 }
1511                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1512                                           &sg_class_member->kobj, "generic");
1513                 if (error)
1514                         pr_err("%s: unable to make symlink 'generic' back "
1515                                "to sg%d\n", __func__, sdp->index);
1516         } else
1517                 pr_warn("%s: sg_sys Invalid\n", __func__);
1518
1519         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1520                     "type %d\n", sdp->index, scsidp->type);
1521
1522         dev_set_drvdata(cl_dev, sdp);
1523
1524         return 0;
1525
1526 cdev_add_err:
1527         write_lock_irqsave(&sg_index_lock, iflags);
1528         idr_remove(&sg_index_idr, sdp->index);
1529         write_unlock_irqrestore(&sg_index_lock, iflags);
1530         kfree(sdp);
1531
1532 out:
1533         put_disk(disk);
1534         if (cdev)
1535                 cdev_del(cdev);
1536         return error;
1537 }
1538
1539 static void
1540 sg_device_destroy(struct kref *kref)
1541 {
1542         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1543         unsigned long flags;
1544
1545         /* CAUTION!  Note that the device can still be found via idr_find()
1546          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1547          * any other cleanup.
1548          */
1549
1550         write_lock_irqsave(&sg_index_lock, flags);
1551         idr_remove(&sg_index_idr, sdp->index);
1552         write_unlock_irqrestore(&sg_index_lock, flags);
1553
1554         SCSI_LOG_TIMEOUT(3,
1555                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1556
1557         put_disk(sdp->disk);
1558         kfree(sdp);
1559 }
1560
1561 static void
1562 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1563 {
1564         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1565         Sg_device *sdp = dev_get_drvdata(cl_dev);
1566         unsigned long iflags;
1567         Sg_fd *sfp;
1568         int val;
1569
1570         if (!sdp)
1571                 return;
1572         /* want sdp->detaching non-zero as soon as possible */
1573         val = atomic_inc_return(&sdp->detaching);
1574         if (val > 1)
1575                 return; /* only want to do following once per device */
1576
1577         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1578                                       "%s\n", __func__));
1579
1580         read_lock_irqsave(&sdp->sfd_lock, iflags);
1581         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1582                 wake_up_interruptible_all(&sfp->read_wait);
1583                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1584         }
1585         wake_up_interruptible_all(&sdp->open_wait);
1586         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1587
1588         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1589         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1590         cdev_del(sdp->cdev);
1591         sdp->cdev = NULL;
1592
1593         kref_put(&sdp->d_ref, sg_device_destroy);
1594 }
1595
1596 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1597 module_param_named(def_reserved_size, def_reserved_size, int,
1598                    S_IRUGO | S_IWUSR);
1599 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1600
1601 MODULE_AUTHOR("Douglas Gilbert");
1602 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1603 MODULE_LICENSE("GPL");
1604 MODULE_VERSION(SG_VERSION_STR);
1605 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1606
1607 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1608                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1609 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1610 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1611
1612 static int __init
1613 init_sg(void)
1614 {
1615         int rc;
1616
1617         if (scatter_elem_sz < PAGE_SIZE) {
1618                 scatter_elem_sz = PAGE_SIZE;
1619                 scatter_elem_sz_prev = scatter_elem_sz;
1620         }
1621         if (def_reserved_size >= 0)
1622                 sg_big_buff = def_reserved_size;
1623         else
1624                 def_reserved_size = sg_big_buff;
1625
1626         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1627                                     SG_MAX_DEVS, "sg");
1628         if (rc)
1629                 return rc;
1630         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1631         if ( IS_ERR(sg_sysfs_class) ) {
1632                 rc = PTR_ERR(sg_sysfs_class);
1633                 goto err_out;
1634         }
1635         sg_sysfs_valid = 1;
1636         rc = scsi_register_interface(&sg_interface);
1637         if (0 == rc) {
1638 #ifdef CONFIG_SCSI_PROC_FS
1639                 sg_proc_init();
1640 #endif                          /* CONFIG_SCSI_PROC_FS */
1641                 return 0;
1642         }
1643         class_destroy(sg_sysfs_class);
1644 err_out:
1645         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1646         return rc;
1647 }
1648
1649 static void __exit
1650 exit_sg(void)
1651 {
1652 #ifdef CONFIG_SCSI_PROC_FS
1653         remove_proc_subtree("scsi/sg", NULL);
1654 #endif                          /* CONFIG_SCSI_PROC_FS */
1655         scsi_unregister_interface(&sg_interface);
1656         class_destroy(sg_sysfs_class);
1657         sg_sysfs_valid = 0;
1658         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1659                                  SG_MAX_DEVS);
1660         idr_destroy(&sg_index_idr);
1661 }
1662
1663 static int
1664 sg_start_req(Sg_request *srp, unsigned char *cmd)
1665 {
1666         int res;
1667         struct request *rq;
1668         struct scsi_request *req;
1669         Sg_fd *sfp = srp->parentfp;
1670         sg_io_hdr_t *hp = &srp->header;
1671         int dxfer_len = (int) hp->dxfer_len;
1672         int dxfer_dir = hp->dxfer_direction;
1673         unsigned int iov_count = hp->iovec_count;
1674         Sg_scatter_hold *req_schp = &srp->data;
1675         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1676         struct request_queue *q = sfp->parentdp->device->request_queue;
1677         struct rq_map_data *md, map_data;
1678         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1679         unsigned char *long_cmdp = NULL;
1680
1681         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1682                                       "sg_start_req: dxfer_len=%d\n",
1683                                       dxfer_len));
1684
1685         if (hp->cmd_len > BLK_MAX_CDB) {
1686                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1687                 if (!long_cmdp)
1688                         return -ENOMEM;
1689         }
1690
1691         /*
1692          * NOTE
1693          *
1694          * With scsi-mq enabled, there are a fixed number of preallocated
1695          * requests equal in number to shost->can_queue.  If all of the
1696          * preallocated requests are already in use, then blk_get_request()
1697          * will sleep until an active command completes, freeing up a request.
1698          * Although waiting in an asynchronous interface is less than ideal, we
1699          * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1700          * not expect an EWOULDBLOCK from this condition.
1701          */
1702         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1703                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1704         if (IS_ERR(rq)) {
1705                 kfree(long_cmdp);
1706                 return PTR_ERR(rq);
1707         }
1708         req = scsi_req(rq);
1709
1710         if (hp->cmd_len > BLK_MAX_CDB)
1711                 req->cmd = long_cmdp;
1712         memcpy(req->cmd, cmd, hp->cmd_len);
1713         req->cmd_len = hp->cmd_len;
1714
1715         srp->rq = rq;
1716         rq->end_io_data = srp;
1717         req->retries = SG_DEFAULT_RETRIES;
1718
1719         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1720                 return 0;
1721
1722         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1723             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1724             !sfp->parentdp->device->host->unchecked_isa_dma &&
1725             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1726                 md = NULL;
1727         else
1728                 md = &map_data;
1729
1730         if (md) {
1731                 mutex_lock(&sfp->f_mutex);
1732                 if (dxfer_len <= rsv_schp->bufflen &&
1733                     !sfp->res_in_use) {
1734                         sfp->res_in_use = 1;
1735                         sg_link_reserve(sfp, srp, dxfer_len);
1736                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1737                         res = -EBUSY; /* sfp->res_in_use == 1 */
1738                         if (dxfer_len > rsv_schp->bufflen)
1739                                 res = -ENOMEM;
1740                         mutex_unlock(&sfp->f_mutex);
1741                         return res;
1742                 } else {
1743                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1744                         if (res) {
1745                                 mutex_unlock(&sfp->f_mutex);
1746                                 return res;
1747                         }
1748                 }
1749                 mutex_unlock(&sfp->f_mutex);
1750
1751                 md->pages = req_schp->pages;
1752                 md->page_order = req_schp->page_order;
1753                 md->nr_entries = req_schp->k_use_sg;
1754                 md->offset = 0;
1755                 md->null_mapped = hp->dxferp ? 0 : 1;
1756                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1757                         md->from_user = 1;
1758                 else
1759                         md->from_user = 0;
1760         }
1761
1762         if (iov_count) {
1763                 struct iovec *iov = NULL;
1764                 struct iov_iter i;
1765
1766                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1767                 if (res < 0)
1768                         return res;
1769
1770                 iov_iter_truncate(&i, hp->dxfer_len);
1771                 if (!iov_iter_count(&i)) {
1772                         kfree(iov);
1773                         return -EINVAL;
1774                 }
1775
1776                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1777                 kfree(iov);
1778         } else
1779                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1780                                       hp->dxfer_len, GFP_ATOMIC);
1781
1782         if (!res) {
1783                 srp->bio = rq->bio;
1784
1785                 if (!md) {
1786                         req_schp->dio_in_use = 1;
1787                         hp->info |= SG_INFO_DIRECT_IO;
1788                 }
1789         }
1790         return res;
1791 }
1792
1793 static int
1794 sg_finish_rem_req(Sg_request *srp)
1795 {
1796         int ret = 0;
1797
1798         Sg_fd *sfp = srp->parentfp;
1799         Sg_scatter_hold *req_schp = &srp->data;
1800
1801         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1802                                       "sg_finish_rem_req: res_used=%d\n",
1803                                       (int) srp->res_used));
1804         if (srp->bio)
1805                 ret = blk_rq_unmap_user(srp->bio);
1806
1807         if (srp->rq) {
1808                 scsi_req_free_cmd(scsi_req(srp->rq));
1809                 blk_put_request(srp->rq);
1810         }
1811
1812         if (srp->res_used)
1813                 sg_unlink_reserve(sfp, srp);
1814         else
1815                 sg_remove_scat(sfp, req_schp);
1816
1817         return ret;
1818 }
1819
1820 static int
1821 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1822 {
1823         int sg_bufflen = tablesize * sizeof(struct page *);
1824         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1825
1826         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1827         if (!schp->pages)
1828                 return -ENOMEM;
1829         schp->sglist_len = sg_bufflen;
1830         return tablesize;       /* number of scat_gath elements allocated */
1831 }
1832
1833 static int
1834 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1835 {
1836         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1837         int sg_tablesize = sfp->parentdp->sg_tablesize;
1838         int blk_size = buff_size, order;
1839         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1840         struct sg_device *sdp = sfp->parentdp;
1841
1842         if (blk_size < 0)
1843                 return -EFAULT;
1844         if (0 == blk_size)
1845                 ++blk_size;     /* don't know why */
1846         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1847         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1848         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1849                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1850                 buff_size, blk_size));
1851
1852         /* N.B. ret_sz carried into this block ... */
1853         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1854         if (mx_sc_elems < 0)
1855                 return mx_sc_elems;     /* most likely -ENOMEM */
1856
1857         num = scatter_elem_sz;
1858         if (unlikely(num != scatter_elem_sz_prev)) {
1859                 if (num < PAGE_SIZE) {
1860                         scatter_elem_sz = PAGE_SIZE;
1861                         scatter_elem_sz_prev = PAGE_SIZE;
1862                 } else
1863                         scatter_elem_sz_prev = num;
1864         }
1865
1866         if (sdp->device->host->unchecked_isa_dma)
1867                 gfp_mask |= GFP_DMA;
1868
1869         order = get_order(num);
1870 retry:
1871         ret_sz = 1 << (PAGE_SHIFT + order);
1872
1873         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1874              k++, rem_sz -= ret_sz) {
1875
1876                 num = (rem_sz > scatter_elem_sz_prev) ?
1877                         scatter_elem_sz_prev : rem_sz;
1878
1879                 schp->pages[k] = alloc_pages(gfp_mask, order);
1880                 if (!schp->pages[k])
1881                         goto out;
1882
1883                 if (num == scatter_elem_sz_prev) {
1884                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1885                                 scatter_elem_sz = ret_sz;
1886                                 scatter_elem_sz_prev = ret_sz;
1887                         }
1888                 }
1889
1890                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1891                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1892                                  k, num, ret_sz));
1893         }               /* end of for loop */
1894
1895         schp->page_order = order;
1896         schp->k_use_sg = k;
1897         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1898                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1899                          k, rem_sz));
1900
1901         schp->bufflen = blk_size;
1902         if (rem_sz > 0) /* must have failed */
1903                 return -ENOMEM;
1904         return 0;
1905 out:
1906         for (i = 0; i < k; i++)
1907                 __free_pages(schp->pages[i], order);
1908
1909         if (--order >= 0)
1910                 goto retry;
1911
1912         return -ENOMEM;
1913 }
1914
1915 static void
1916 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1917 {
1918         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1919                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1920         if (schp->pages && schp->sglist_len > 0) {
1921                 if (!schp->dio_in_use) {
1922                         int k;
1923
1924                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1925                                 SCSI_LOG_TIMEOUT(5,
1926                                         sg_printk(KERN_INFO, sfp->parentdp,
1927                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1928                                         k, schp->pages[k]));
1929                                 __free_pages(schp->pages[k], schp->page_order);
1930                         }
1931
1932                         kfree(schp->pages);
1933                 }
1934         }
1935         memset(schp, 0, sizeof (*schp));
1936 }
1937
1938 static int
1939 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1940 {
1941         Sg_scatter_hold *schp = &srp->data;
1942         int k, num;
1943
1944         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1945                          "sg_read_oxfer: num_read_xfer=%d\n",
1946                          num_read_xfer));
1947         if ((!outp) || (num_read_xfer <= 0))
1948                 return 0;
1949
1950         num = 1 << (PAGE_SHIFT + schp->page_order);
1951         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1952                 if (num > num_read_xfer) {
1953                         if (copy_to_user(outp, page_address(schp->pages[k]),
1954                                            num_read_xfer))
1955                                 return -EFAULT;
1956                         break;
1957                 } else {
1958                         if (copy_to_user(outp, page_address(schp->pages[k]),
1959                                            num))
1960                                 return -EFAULT;
1961                         num_read_xfer -= num;
1962                         if (num_read_xfer <= 0)
1963                                 break;
1964                         outp += num;
1965                 }
1966         }
1967
1968         return 0;
1969 }
1970
1971 static void
1972 sg_build_reserve(Sg_fd * sfp, int req_size)
1973 {
1974         Sg_scatter_hold *schp = &sfp->reserve;
1975
1976         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1977                          "sg_build_reserve: req_size=%d\n", req_size));
1978         do {
1979                 if (req_size < PAGE_SIZE)
1980                         req_size = PAGE_SIZE;
1981                 if (0 == sg_build_indirect(schp, sfp, req_size))
1982                         return;
1983                 else
1984                         sg_remove_scat(sfp, schp);
1985                 req_size >>= 1; /* divide by 2 */
1986         } while (req_size > (PAGE_SIZE / 2));
1987 }
1988
1989 static void
1990 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1991 {
1992         Sg_scatter_hold *req_schp = &srp->data;
1993         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1994         int k, num, rem;
1995
1996         srp->res_used = 1;
1997         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1998                          "sg_link_reserve: size=%d\n", size));
1999         rem = size;
2000
2001         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2002         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2003                 if (rem <= num) {
2004                         req_schp->k_use_sg = k + 1;
2005                         req_schp->sglist_len = rsv_schp->sglist_len;
2006                         req_schp->pages = rsv_schp->pages;
2007
2008                         req_schp->bufflen = size;
2009                         req_schp->page_order = rsv_schp->page_order;
2010                         break;
2011                 } else
2012                         rem -= num;
2013         }
2014
2015         if (k >= rsv_schp->k_use_sg)
2016                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2017                                  "sg_link_reserve: BAD size\n"));
2018 }
2019
2020 static void
2021 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2022 {
2023         Sg_scatter_hold *req_schp = &srp->data;
2024
2025         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2026                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2027                                       (int) req_schp->k_use_sg));
2028         req_schp->k_use_sg = 0;
2029         req_schp->bufflen = 0;
2030         req_schp->pages = NULL;
2031         req_schp->page_order = 0;
2032         req_schp->sglist_len = 0;
2033         srp->res_used = 0;
2034         /* Called without mutex lock to avoid deadlock */
2035         sfp->res_in_use = 0;
2036 }
2037
2038 static Sg_request *
2039 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2040 {
2041         Sg_request *resp;
2042         unsigned long iflags;
2043
2044         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2045         list_for_each_entry(resp, &sfp->rq_list, entry) {
2046                 /* look for requests that are ready + not SG_IO owned */
2047                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2048                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2049                         resp->done = 2; /* guard against other readers */
2050                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2051                         return resp;
2052                 }
2053         }
2054         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2055         return NULL;
2056 }
2057
2058 /* always adds to end of list */
2059 static Sg_request *
2060 sg_add_request(Sg_fd * sfp)
2061 {
2062         int k;
2063         unsigned long iflags;
2064         Sg_request *rp = sfp->req_arr;
2065
2066         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2067         if (!list_empty(&sfp->rq_list)) {
2068                 if (!sfp->cmd_q)
2069                         goto out_unlock;
2070
2071                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2072                         if (!rp->parentfp)
2073                                 break;
2074                 }
2075                 if (k >= SG_MAX_QUEUE)
2076                         goto out_unlock;
2077         }
2078         memset(rp, 0, sizeof (Sg_request));
2079         rp->parentfp = sfp;
2080         rp->header.duration = jiffies_to_msecs(jiffies);
2081         list_add_tail(&rp->entry, &sfp->rq_list);
2082         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2083         return rp;
2084 out_unlock:
2085         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2086         return NULL;
2087 }
2088
2089 /* Return of 1 for found; 0 for not found */
2090 static int
2091 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2092 {
2093         unsigned long iflags;
2094         int res = 0;
2095
2096         if (!sfp || !srp || list_empty(&sfp->rq_list))
2097                 return res;
2098         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2099         if (!list_empty(&srp->entry)) {
2100                 list_del(&srp->entry);
2101                 srp->parentfp = NULL;
2102                 res = 1;
2103         }
2104         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2105         return res;
2106 }
2107
2108 static Sg_fd *
2109 sg_add_sfp(Sg_device * sdp)
2110 {
2111         Sg_fd *sfp;
2112         unsigned long iflags;
2113         int bufflen;
2114
2115         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2116         if (!sfp)
2117                 return ERR_PTR(-ENOMEM);
2118
2119         init_waitqueue_head(&sfp->read_wait);
2120         rwlock_init(&sfp->rq_list_lock);
2121         INIT_LIST_HEAD(&sfp->rq_list);
2122         kref_init(&sfp->f_ref);
2123         mutex_init(&sfp->f_mutex);
2124         sfp->timeout = SG_DEFAULT_TIMEOUT;
2125         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2126         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2127         sfp->cmd_q = SG_DEF_COMMAND_Q;
2128         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2129         sfp->parentdp = sdp;
2130         write_lock_irqsave(&sdp->sfd_lock, iflags);
2131         if (atomic_read(&sdp->detaching)) {
2132                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2133                 kfree(sfp);
2134                 return ERR_PTR(-ENODEV);
2135         }
2136         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2137         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2138         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2139                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2140         if (unlikely(sg_big_buff != def_reserved_size))
2141                 sg_big_buff = def_reserved_size;
2142
2143         bufflen = min_t(int, sg_big_buff,
2144                         max_sectors_bytes(sdp->device->request_queue));
2145         sg_build_reserve(sfp, bufflen);
2146         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2147                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2148                                       sfp->reserve.bufflen,
2149                                       sfp->reserve.k_use_sg));
2150
2151         kref_get(&sdp->d_ref);
2152         __module_get(THIS_MODULE);
2153         return sfp;
2154 }
2155
2156 static void
2157 sg_remove_sfp_usercontext(struct work_struct *work)
2158 {
2159         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2160         struct sg_device *sdp = sfp->parentdp;
2161         Sg_request *srp;
2162         unsigned long iflags;
2163
2164         /* Cleanup any responses which were never read(). */
2165         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2166         while (!list_empty(&sfp->rq_list)) {
2167                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2168                 sg_finish_rem_req(srp);
2169                 list_del(&srp->entry);
2170                 srp->parentfp = NULL;
2171         }
2172         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2173
2174         if (sfp->reserve.bufflen > 0) {
2175                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2176                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2177                                 (int) sfp->reserve.bufflen,
2178                                 (int) sfp->reserve.k_use_sg));
2179                 sg_remove_scat(sfp, &sfp->reserve);
2180         }
2181
2182         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2183                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2184         kfree(sfp);
2185
2186         scsi_device_put(sdp->device);
2187         kref_put(&sdp->d_ref, sg_device_destroy);
2188         module_put(THIS_MODULE);
2189 }
2190
2191 static void
2192 sg_remove_sfp(struct kref *kref)
2193 {
2194         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2195         struct sg_device *sdp = sfp->parentdp;
2196         unsigned long iflags;
2197
2198         write_lock_irqsave(&sdp->sfd_lock, iflags);
2199         list_del(&sfp->sfd_siblings);
2200         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2201
2202         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2203         schedule_work(&sfp->ew.work);
2204 }
2205
2206 #ifdef CONFIG_SCSI_PROC_FS
2207 static int
2208 sg_idr_max_id(int id, void *p, void *data)
2209 {
2210         int *k = data;
2211
2212         if (*k < id)
2213                 *k = id;
2214
2215         return 0;
2216 }
2217
2218 static int
2219 sg_last_dev(void)
2220 {
2221         int k = -1;
2222         unsigned long iflags;
2223
2224         read_lock_irqsave(&sg_index_lock, iflags);
2225         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2226         read_unlock_irqrestore(&sg_index_lock, iflags);
2227         return k + 1;           /* origin 1 */
2228 }
2229 #endif
2230
2231 /* must be called with sg_index_lock held */
2232 static Sg_device *sg_lookup_dev(int dev)
2233 {
2234         return idr_find(&sg_index_idr, dev);
2235 }
2236
2237 static Sg_device *
2238 sg_get_dev(int dev)
2239 {
2240         struct sg_device *sdp;
2241         unsigned long flags;
2242
2243         read_lock_irqsave(&sg_index_lock, flags);
2244         sdp = sg_lookup_dev(dev);
2245         if (!sdp)
2246                 sdp = ERR_PTR(-ENXIO);
2247         else if (atomic_read(&sdp->detaching)) {
2248                 /* If sdp->detaching, then the refcount may already be 0, in
2249                  * which case it would be a bug to do kref_get().
2250                  */
2251                 sdp = ERR_PTR(-ENODEV);
2252         } else
2253                 kref_get(&sdp->d_ref);
2254         read_unlock_irqrestore(&sg_index_lock, flags);
2255
2256         return sdp;
2257 }
2258
2259 #ifdef CONFIG_SCSI_PROC_FS
2260 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2261
2262 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2263 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2264                                   size_t count, loff_t *off);
2265 static const struct file_operations adio_fops = {
2266         .owner = THIS_MODULE,
2267         .open = sg_proc_single_open_adio,
2268         .read = seq_read,
2269         .llseek = seq_lseek,
2270         .write = sg_proc_write_adio,
2271         .release = single_release,
2272 };
2273
2274 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2275 static ssize_t sg_proc_write_dressz(struct file *filp,
2276                 const char __user *buffer, size_t count, loff_t *off);
2277 static const struct file_operations dressz_fops = {
2278         .owner = THIS_MODULE,
2279         .open = sg_proc_single_open_dressz,
2280         .read = seq_read,
2281         .llseek = seq_lseek,
2282         .write = sg_proc_write_dressz,
2283         .release = single_release,
2284 };
2285
2286 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2287 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2288 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2289 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2290 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2291 static void dev_seq_stop(struct seq_file *s, void *v);
2292 static const struct seq_operations dev_seq_ops = {
2293         .start = dev_seq_start,
2294         .next  = dev_seq_next,
2295         .stop  = dev_seq_stop,
2296         .show  = sg_proc_seq_show_dev,
2297 };
2298
2299 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2300 static const struct seq_operations devstrs_seq_ops = {
2301         .start = dev_seq_start,
2302         .next  = dev_seq_next,
2303         .stop  = dev_seq_stop,
2304         .show  = sg_proc_seq_show_devstrs,
2305 };
2306
2307 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2308 static const struct seq_operations debug_seq_ops = {
2309         .start = dev_seq_start,
2310         .next  = dev_seq_next,
2311         .stop  = dev_seq_stop,
2312         .show  = sg_proc_seq_show_debug,
2313 };
2314
2315 static int
2316 sg_proc_init(void)
2317 {
2318         struct proc_dir_entry *p;
2319
2320         p = proc_mkdir("scsi/sg", NULL);
2321         if (!p)
2322                 return 1;
2323
2324         proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
2325         proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2326         proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
2327         proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2328         proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2329         proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2330         proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2331         return 0;
2332 }
2333
2334
2335 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2336 {
2337         seq_printf(s, "%d\n", *((int *)s->private));
2338         return 0;
2339 }
2340
2341 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2342 {
2343         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2344 }
2345
2346 static ssize_t
2347 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2348                    size_t count, loff_t *off)
2349 {
2350         int err;
2351         unsigned long num;
2352
2353         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2354                 return -EACCES;
2355         err = kstrtoul_from_user(buffer, count, 0, &num);
2356         if (err)
2357                 return err;
2358         sg_allow_dio = num ? 1 : 0;
2359         return count;
2360 }
2361
2362 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2363 {
2364         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2365 }
2366
2367 static ssize_t
2368 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2369                      size_t count, loff_t *off)
2370 {
2371         int err;
2372         unsigned long k = ULONG_MAX;
2373
2374         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2375                 return -EACCES;
2376
2377         err = kstrtoul_from_user(buffer, count, 0, &k);
2378         if (err)
2379                 return err;
2380         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2381                 sg_big_buff = k;
2382                 return count;
2383         }
2384         return -ERANGE;
2385 }
2386
2387 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2388 {
2389         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2390                    sg_version_date);
2391         return 0;
2392 }
2393
2394 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2395 {
2396         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2397         return 0;
2398 }
2399
2400 struct sg_proc_deviter {
2401         loff_t  index;
2402         size_t  max;
2403 };
2404
2405 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2406 {
2407         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2408
2409         s->private = it;
2410         if (! it)
2411                 return NULL;
2412
2413         it->index = *pos;
2414         it->max = sg_last_dev();
2415         if (it->index >= it->max)
2416                 return NULL;
2417         return it;
2418 }
2419
2420 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2421 {
2422         struct sg_proc_deviter * it = s->private;
2423
2424         *pos = ++it->index;
2425         return (it->index < it->max) ? it : NULL;
2426 }
2427
2428 static void dev_seq_stop(struct seq_file *s, void *v)
2429 {
2430         kfree(s->private);
2431 }
2432
2433 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2434 {
2435         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2436         Sg_device *sdp;
2437         struct scsi_device *scsidp;
2438         unsigned long iflags;
2439
2440         read_lock_irqsave(&sg_index_lock, iflags);
2441         sdp = it ? sg_lookup_dev(it->index) : NULL;
2442         if ((NULL == sdp) || (NULL == sdp->device) ||
2443             (atomic_read(&sdp->detaching)))
2444                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2445         else {
2446                 scsidp = sdp->device;
2447                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2448                               scsidp->host->host_no, scsidp->channel,
2449                               scsidp->id, scsidp->lun, (int) scsidp->type,
2450                               1,
2451                               (int) scsidp->queue_depth,
2452                               (int) atomic_read(&scsidp->device_busy),
2453                               (int) scsi_device_online(scsidp));
2454         }
2455         read_unlock_irqrestore(&sg_index_lock, iflags);
2456         return 0;
2457 }
2458
2459 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2460 {
2461         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2462         Sg_device *sdp;
2463         struct scsi_device *scsidp;
2464         unsigned long iflags;
2465
2466         read_lock_irqsave(&sg_index_lock, iflags);
2467         sdp = it ? sg_lookup_dev(it->index) : NULL;
2468         scsidp = sdp ? sdp->device : NULL;
2469         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2470                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2471                            scsidp->vendor, scsidp->model, scsidp->rev);
2472         else
2473                 seq_puts(s, "<no active device>\n");
2474         read_unlock_irqrestore(&sg_index_lock, iflags);
2475         return 0;
2476 }
2477
2478 /* must be called while holding sg_index_lock */
2479 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2480 {
2481         int k, new_interface, blen, usg;
2482         Sg_request *srp;
2483         Sg_fd *fp;
2484         const sg_io_hdr_t *hp;
2485         const char * cp;
2486         unsigned int ms;
2487
2488         k = 0;
2489         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2490                 k++;
2491                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2492                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2493                            "(res)sgat=%d low_dma=%d\n", k,
2494                            jiffies_to_msecs(fp->timeout),
2495                            fp->reserve.bufflen,
2496                            (int) fp->reserve.k_use_sg,
2497                            (int) sdp->device->host->unchecked_isa_dma);
2498                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2499                            (int) fp->cmd_q, (int) fp->force_packid,
2500                            (int) fp->keep_orphan);
2501                 list_for_each_entry(srp, &fp->rq_list, entry) {
2502                         hp = &srp->header;
2503                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2504                         if (srp->res_used) {
2505                                 if (new_interface &&
2506                                     (SG_FLAG_MMAP_IO & hp->flags))
2507                                         cp = "     mmap>> ";
2508                                 else
2509                                         cp = "     rb>> ";
2510                         } else {
2511                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2512                                         cp = "     dio>> ";
2513                                 else
2514                                         cp = "     ";
2515                         }
2516                         seq_puts(s, cp);
2517                         blen = srp->data.bufflen;
2518                         usg = srp->data.k_use_sg;
2519                         seq_puts(s, srp->done ?
2520                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2521                                   : "act:");
2522                         seq_printf(s, " id=%d blen=%d",
2523                                    srp->header.pack_id, blen);
2524                         if (srp->done)
2525                                 seq_printf(s, " dur=%d", hp->duration);
2526                         else {
2527                                 ms = jiffies_to_msecs(jiffies);
2528                                 seq_printf(s, " t_o/elap=%d/%d",
2529                                         (new_interface ? hp->timeout :
2530                                                   jiffies_to_msecs(fp->timeout)),
2531                                         (ms > hp->duration ? ms - hp->duration : 0));
2532                         }
2533                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2534                                    (int) srp->data.cmd_opcode);
2535                 }
2536                 if (list_empty(&fp->rq_list))
2537                         seq_puts(s, "     No requests active\n");
2538                 read_unlock(&fp->rq_list_lock);
2539         }
2540 }
2541
2542 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2543 {
2544         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2545         Sg_device *sdp;
2546         unsigned long iflags;
2547
2548         if (it && (0 == it->index))
2549                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2550                            (int)it->max, sg_big_buff);
2551
2552         read_lock_irqsave(&sg_index_lock, iflags);
2553         sdp = it ? sg_lookup_dev(it->index) : NULL;
2554         if (NULL == sdp)
2555                 goto skip;
2556         read_lock(&sdp->sfd_lock);
2557         if (!list_empty(&sdp->sfds)) {
2558                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2559                 if (atomic_read(&sdp->detaching))
2560                         seq_puts(s, "detaching pending close ");
2561                 else if (sdp->device) {
2562                         struct scsi_device *scsidp = sdp->device;
2563
2564                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2565                                    scsidp->host->host_no,
2566                                    scsidp->channel, scsidp->id,
2567                                    scsidp->lun,
2568                                    scsidp->host->hostt->emulated);
2569                 }
2570                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2571                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2572                 sg_proc_debug_helper(s, sdp);
2573         }
2574         read_unlock(&sdp->sfd_lock);
2575 skip:
2576         read_unlock_irqrestore(&sg_index_lock, iflags);
2577         return 0;
2578 }
2579
2580 #endif                          /* CONFIG_SCSI_PROC_FS */
2581
2582 module_init(init_sg);
2583 module_exit(exit_sg);