drivers/scsi/sg.c

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