linux/drivers/scsi/sg.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  History:
   4 *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   5 *           to allow user process control of SCSI devices.
   6 *  Development Sponsored by Killy Corp. NY NY
   7 *
   8 * Original driver (sg.c):
   9 *        Copyright (C) 1992 Lawrence Foard
  10 * Version 2 and 3 extensions to driver:
  11 *        Copyright (C) 1998 - 2014 Douglas Gilbert
  12 */
  13
  14static int sg_version_num = 30536;      /* 2 digits for each component */
  15#define SG_VERSION_STR "3.5.36"
  16
  17/*
  18 *  D. P. Gilbert (dgilbert@interlog.com), notes:
  19 *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  20 *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  21 *        (otherwise the macros compile to empty statements).
  22 *
  23 */
  24#include <linux/module.h>
  25
  26#include <linux/fs.h>
  27#include <linux/kernel.h>
  28#include <linux/sched.h>
  29#include <linux/string.h>
  30#include <linux/mm.h>
  31#include <linux/errno.h>
  32#include <linux/mtio.h>
  33#include <linux/ioctl.h>
  34#include <linux/slab.h>
  35#include <linux/fcntl.h>
  36#include <linux/init.h>
  37#include <linux/poll.h>
  38#include <linux/moduleparam.h>
  39#include <linux/cdev.h>
  40#include <linux/idr.h>
  41#include <linux/seq_file.h>
  42#include <linux/blkdev.h>
  43#include <linux/delay.h>
  44#include <linux/blktrace_api.h>
  45#include <linux/mutex.h>
  46#include <linux/atomic.h>
  47#include <linux/ratelimit.h>
  48#include <linux/uio.h>
  49#include <linux/cred.h> /* for sg_check_file_access() */
  50
  51#include "scsi.h"
  52#include <scsi/scsi_dbg.h>
  53#include <scsi/scsi_host.h>
  54#include <scsi/scsi_driver.h>
  55#include <scsi/scsi_ioctl.h>
  56#include <scsi/sg.h>
  57
  58#include "scsi_logging.h"
  59
  60#ifdef CONFIG_SCSI_PROC_FS
  61#include <linux/proc_fs.h>
  62static char *sg_version_date = "20140603";
  63
  64static int sg_proc_init(void);
  65#endif
  66
  67#define SG_ALLOW_DIO_DEF 0
  68
  69#define SG_MAX_DEVS 32768
  70
  71/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  72 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  73 * than 16 bytes are "variable length" whose length is a multiple of 4
  74 */
  75#define SG_MAX_CDB_SIZE 252
  76
  77#define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  78
  79int sg_big_buff = SG_DEF_RESERVED_SIZE;
  80/* N.B. This variable is readable and writeable via
  81   /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  82   of this size (or less if there is not enough memory) will be reserved
  83   for use by this file descriptor. [Deprecated usage: this variable is also
  84   readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  85   the kernel (i.e. it is not a module).] */
  86static int def_reserved_size = -1;      /* picks up init parameter */
  87static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  88
  89static int scatter_elem_sz = SG_SCATTER_SZ;
  90static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  91
  92#define SG_SECTOR_SZ 512
  93
  94static int sg_add_device(struct device *, struct class_interface *);
  95static void sg_remove_device(struct device *, struct class_interface *);
  96
  97static DEFINE_IDR(sg_index_idr);
  98static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
  99                                                           file descriptor list for device */
 100
 101static struct class_interface sg_interface = {
 102        .add_dev        = sg_add_device,
 103        .remove_dev     = sg_remove_device,
 104};
 105
 106typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 107        unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 108        unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 109        unsigned bufflen;       /* Size of (aggregate) data buffer */
 110        struct page **pages;
 111        int page_order;
 112        char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 113        unsigned char cmd_opcode; /* first byte of command */
 114} Sg_scatter_hold;
 115
 116struct sg_device;               /* forward declarations */
 117struct sg_fd;
 118
 119typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 120        struct list_head entry; /* list entry */
 121        struct sg_fd *parentfp; /* NULL -> not in use */
 122        Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 123        sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 124        unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 125        char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 126        char orphan;            /* 1 -> drop on sight, 0 -> normal */
 127        char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 128        /* done protected by rq_list_lock */
 129        char done;              /* 0->before bh, 1->before read, 2->read */
 130        struct request *rq;
 131        struct bio *bio;
 132        struct execute_work ew;
 133} Sg_request;
 134
 135typedef struct sg_fd {          /* holds the state of a file descriptor */
 136        struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 137        struct sg_device *parentdp;     /* owning device */
 138        wait_queue_head_t read_wait;    /* queue read until command done */
 139        rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 140        struct mutex f_mutex;   /* protect against changes in this fd */
 141        int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 142        int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 143        Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 144        struct list_head rq_list; /* head of request list */
 145        struct fasync_struct *async_qp; /* used by asynchronous notification */
 146        Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 147        char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 148        char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 149        unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 150        char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 151        char mmap_called;       /* 0 -> mmap() never called on this fd */
 152        char res_in_use;        /* 1 -> 'reserve' array in use */
 153        struct kref f_ref;
 154        struct execute_work ew;
 155} Sg_fd;
 156
 157typedef struct sg_device { /* holds the state of each scsi generic device */
 158        struct scsi_device *device;
 159        wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 160        struct mutex open_rel_lock;     /* held when in open() or release() */
 161        int sg_tablesize;       /* adapter's max scatter-gather table size */
 162        u32 index;              /* device index number */
 163        struct list_head sfds;
 164        rwlock_t sfd_lock;      /* protect access to sfd list */
 165        atomic_t detaching;     /* 0->device usable, 1->device detaching */
 166        bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 167        int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 168        char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 169        struct gendisk *disk;
 170        struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 171        struct kref d_ref;
 172} Sg_device;
 173
 174/* tasklet or soft irq callback */
 175static void sg_rq_end_io(struct request *rq, blk_status_t status);
 176static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 177static int sg_finish_rem_req(Sg_request * srp);
 178static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 179static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 180                           Sg_request * srp);
 181static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 182                        const char __user *buf, size_t count, int blocking,
 183                        int read_only, int sg_io_owned, Sg_request **o_srp);
 184static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 185                           unsigned char *cmnd, int timeout, int blocking);
 186static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 187static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 188static void sg_build_reserve(Sg_fd * sfp, int req_size);
 189static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 190static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 191static Sg_fd *sg_add_sfp(Sg_device * sdp);
 192static void sg_remove_sfp(struct kref *);
 193static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 194static Sg_request *sg_add_request(Sg_fd * sfp);
 195static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 196static Sg_device *sg_get_dev(int dev);
 197static void sg_device_destroy(struct kref *kref);
 198
 199#define SZ_SG_HEADER sizeof(struct sg_header)
 200#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 201#define SZ_SG_IOVEC sizeof(sg_iovec_t)
 202#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 203
 204#define sg_printk(prefix, sdp, fmt, a...) \
 205        sdev_prefix_printk(prefix, (sdp)->device,               \
 206                           (sdp)->disk->disk_name, fmt, ##a)
 207
 208/*
 209 * The SCSI interfaces that use read() and write() as an asynchronous variant of
 210 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
 211 * to trigger read() and write() calls from various contexts with elevated
 212 * privileges. This can lead to kernel memory corruption (e.g. if these
 213 * interfaces are called through splice()) and privilege escalation inside
 214 * userspace (e.g. if a process with access to such a device passes a file
 215 * descriptor to a SUID binary as stdin/stdout/stderr).
 216 *
 217 * This function provides protection for the legacy API by restricting the
 218 * calling context.
 219 */
 220static int sg_check_file_access(struct file *filp, const char *caller)
 221{
 222        if (filp->f_cred != current_real_cred()) {
 223                pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 224                        caller, task_tgid_vnr(current), current->comm);
 225                return -EPERM;
 226        }
 227        if (uaccess_kernel()) {
 228                pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
 229                        caller, task_tgid_vnr(current), current->comm);
 230                return -EACCES;
 231        }
 232        return 0;
 233}
 234
 235static int sg_allow_access(struct file *filp, unsigned char *cmd)
 236{
 237        struct sg_fd *sfp = filp->private_data;
 238
 239        if (sfp->parentdp->device->type == TYPE_SCANNER)
 240                return 0;
 241
 242        return blk_verify_command(cmd, filp->f_mode);
 243}
 244
 245static int
 246open_wait(Sg_device *sdp, int flags)
 247{
 248        int retval = 0;
 249
 250        if (flags & O_EXCL) {
 251                while (sdp->open_cnt > 0) {
 252                        mutex_unlock(&sdp->open_rel_lock);
 253                        retval = wait_event_interruptible(sdp->open_wait,
 254                                        (atomic_read(&sdp->detaching) ||
 255                                         !sdp->open_cnt));
 256                        mutex_lock(&sdp->open_rel_lock);
 257
 258                        if (retval) /* -ERESTARTSYS */
 259                                return retval;
 260                        if (atomic_read(&sdp->detaching))
 261                                return -ENODEV;
 262                }
 263        } else {
 264                while (sdp->exclude) {
 265                        mutex_unlock(&sdp->open_rel_lock);
 266                        retval = wait_event_interruptible(sdp->open_wait,
 267                                        (atomic_read(&sdp->detaching) ||
 268                                         !sdp->exclude));
 269                        mutex_lock(&sdp->open_rel_lock);
 270
 271                        if (retval) /* -ERESTARTSYS */
 272                                return retval;
 273                        if (atomic_read(&sdp->detaching))
 274                                return -ENODEV;
 275                }
 276        }
 277
 278        return retval;
 279}
 280
 281/* Returns 0 on success, else a negated errno value */
 282static int
 283sg_open(struct inode *inode, struct file *filp)
 284{
 285        int dev = iminor(inode);
 286        int flags = filp->f_flags;
 287        struct request_queue *q;
 288        Sg_device *sdp;
 289        Sg_fd *sfp;
 290        int retval;
 291
 292        nonseekable_open(inode, filp);
 293        if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 294                return -EPERM; /* Can't lock it with read only access */
 295        sdp = sg_get_dev(dev);
 296        if (IS_ERR(sdp))
 297                return PTR_ERR(sdp);
 298
 299        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 300                                      "sg_open: flags=0x%x\n", flags));
 301
 302        /* This driver's module count bumped by fops_get in <linux/fs.h> */
 303        /* Prevent the device driver from vanishing while we sleep */
 304        retval = scsi_device_get(sdp->device);
 305        if (retval)
 306                goto sg_put;
 307
 308        retval = scsi_autopm_get_device(sdp->device);
 309        if (retval)
 310                goto sdp_put;
 311
 312        /* scsi_block_when_processing_errors() may block so bypass
 313         * check if O_NONBLOCK. Permits SCSI commands to be issued
 314         * during error recovery. Tread carefully. */
 315        if (!((flags & O_NONBLOCK) ||
 316              scsi_block_when_processing_errors(sdp->device))) {
 317                retval = -ENXIO;
 318                /* we are in error recovery for this device */
 319                goto error_out;
 320        }
 321
 322        mutex_lock(&sdp->open_rel_lock);
 323        if (flags & O_NONBLOCK) {
 324                if (flags & O_EXCL) {
 325                        if (sdp->open_cnt > 0) {
 326                                retval = -EBUSY;
 327                                goto error_mutex_locked;
 328                        }
 329                } else {
 330                        if (sdp->exclude) {
 331                                retval = -EBUSY;
 332                                goto error_mutex_locked;
 333                        }
 334                }
 335        } else {
 336                retval = open_wait(sdp, flags);
 337                if (retval) /* -ERESTARTSYS or -ENODEV */
 338                        goto error_mutex_locked;
 339        }
 340
 341        /* N.B. at this point we are holding the open_rel_lock */
 342        if (flags & O_EXCL)
 343                sdp->exclude = true;
 344
 345        if (sdp->open_cnt < 1) {  /* no existing opens */
 346                sdp->sgdebug = 0;
 347                q = sdp->device->request_queue;
 348                sdp->sg_tablesize = queue_max_segments(q);
 349        }
 350        sfp = sg_add_sfp(sdp);
 351        if (IS_ERR(sfp)) {
 352                retval = PTR_ERR(sfp);
 353                goto out_undo;
 354        }
 355
 356        filp->private_data = sfp;
 357        sdp->open_cnt++;
 358        mutex_unlock(&sdp->open_rel_lock);
 359
 360        retval = 0;
 361sg_put:
 362        kref_put(&sdp->d_ref, sg_device_destroy);
 363        return retval;
 364
 365out_undo:
 366        if (flags & O_EXCL) {
 367                sdp->exclude = false;   /* undo if error */
 368                wake_up_interruptible(&sdp->open_wait);
 369        }
 370error_mutex_locked:
 371        mutex_unlock(&sdp->open_rel_lock);
 372error_out:
 373        scsi_autopm_put_device(sdp->device);
 374sdp_put:
 375        scsi_device_put(sdp->device);
 376        goto sg_put;
 377}
 378
 379/* Release resources associated with a successful sg_open()
 380 * Returns 0 on success, else a negated errno value */
 381static int
 382sg_release(struct inode *inode, struct file *filp)
 383{
 384        Sg_device *sdp;
 385        Sg_fd *sfp;
 386
 387        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 388                return -ENXIO;
 389        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 390
 391        mutex_lock(&sdp->open_rel_lock);
 392        scsi_autopm_put_device(sdp->device);
 393        kref_put(&sfp->f_ref, sg_remove_sfp);
 394        sdp->open_cnt--;
 395
 396        /* possibly many open()s waiting on exlude clearing, start many;
 397         * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 398        if (sdp->exclude) {
 399                sdp->exclude = false;
 400                wake_up_interruptible_all(&sdp->open_wait);
 401        } else if (0 == sdp->open_cnt) {
 402                wake_up_interruptible(&sdp->open_wait);
 403        }
 404        mutex_unlock(&sdp->open_rel_lock);
 405        return 0;
 406}
 407
 408static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
 409{
 410        struct sg_header __user *old_hdr = buf;
 411        int reply_len;
 412
 413        if (count >= SZ_SG_HEADER) {
 414                /* negative reply_len means v3 format, otherwise v1/v2 */
 415                if (get_user(reply_len, &old_hdr->reply_len))
 416                        return -EFAULT;
 417
 418                if (reply_len >= 0)
 419                        return get_user(*pack_id, &old_hdr->pack_id);
 420
 421                if (in_compat_syscall() &&
 422                    count >= sizeof(struct compat_sg_io_hdr)) {
 423                        struct compat_sg_io_hdr __user *hp = buf;
 424
 425                        return get_user(*pack_id, &hp->pack_id);
 426                }
 427
 428                if (count >= sizeof(struct sg_io_hdr)) {
 429                        struct sg_io_hdr __user *hp = buf;
 430
 431                        return get_user(*pack_id, &hp->pack_id);
 432                }
 433        }
 434
 435        /* no valid header was passed, so ignore the pack_id */
 436        *pack_id = -1;
 437        return 0;
 438}
 439
 440static ssize_t
 441sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 442{
 443        Sg_device *sdp;
 444        Sg_fd *sfp;
 445        Sg_request *srp;
 446        int req_pack_id = -1;
 447        sg_io_hdr_t *hp;
 448        struct sg_header *old_hdr;
 449        int retval;
 450
 451        /*
 452         * This could cause a response to be stranded. Close the associated
 453         * file descriptor to free up any resources being held.
 454         */
 455        retval = sg_check_file_access(filp, __func__);
 456        if (retval)
 457                return retval;
 458
 459        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 460                return -ENXIO;
 461        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 462                                      "sg_read: count=%d\n", (int) count));
 463
 464        if (sfp->force_packid)
 465                retval = get_sg_io_pack_id(&req_pack_id, buf, count);
 466        if (retval)
 467                return retval;
 468
 469        srp = sg_get_rq_mark(sfp, req_pack_id);
 470        if (!srp) {             /* now wait on packet to arrive */
 471                if (atomic_read(&sdp->detaching))
 472                        return -ENODEV;
 473                if (filp->f_flags & O_NONBLOCK)
 474                        return -EAGAIN;
 475                retval = wait_event_interruptible(sfp->read_wait,
 476                        (atomic_read(&sdp->detaching) ||
 477                        (srp = sg_get_rq_mark(sfp, req_pack_id))));
 478                if (atomic_read(&sdp->detaching))
 479                        return -ENODEV;
 480                if (retval)
 481                        /* -ERESTARTSYS as signal hit process */
 482                        return retval;
 483        }
 484        if (srp->header.interface_id != '\0')
 485                return sg_new_read(sfp, buf, count, srp);
 486
 487        hp = &srp->header;
 488        old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
 489        if (!old_hdr)
 490                return -ENOMEM;
 491
 492        old_hdr->reply_len = (int) hp->timeout;
 493        old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 494        old_hdr->pack_id = hp->pack_id;
 495        old_hdr->twelve_byte =
 496            ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 497        old_hdr->target_status = hp->masked_status;
 498        old_hdr->host_status = hp->host_status;
 499        old_hdr->driver_status = hp->driver_status;
 500        if ((CHECK_CONDITION & hp->masked_status) ||
 501            (srp->sense_b[0] & 0x70) == 0x70) {
 502                old_hdr->driver_status = DRIVER_SENSE;
 503                memcpy(old_hdr->sense_buffer, srp->sense_b,
 504                       sizeof (old_hdr->sense_buffer));
 505        }
 506        switch (hp->host_status) {
 507        /* This setup of 'result' is for backward compatibility and is best
 508           ignored by the user who should use target, host + driver status */
 509        case DID_OK:
 510        case DID_PASSTHROUGH:
 511        case DID_SOFT_ERROR:
 512                old_hdr->result = 0;
 513                break;
 514        case DID_NO_CONNECT:
 515        case DID_BUS_BUSY:
 516        case DID_TIME_OUT:
 517                old_hdr->result = EBUSY;
 518                break;
 519        case DID_BAD_TARGET:
 520        case DID_ABORT:
 521        case DID_PARITY:
 522        case DID_RESET:
 523        case DID_BAD_INTR:
 524                old_hdr->result = EIO;
 525                break;
 526        case DID_ERROR:
 527                old_hdr->result = (srp->sense_b[0] == 0 && 
 528                                  hp->masked_status == GOOD) ? 0 : EIO;
 529                break;
 530        default:
 531                old_hdr->result = EIO;
 532                break;
 533        }
 534
 535        /* Now copy the result back to the user buffer.  */
 536        if (count >= SZ_SG_HEADER) {
 537                if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 538                        retval = -EFAULT;
 539                        goto free_old_hdr;
 540                }
 541                buf += SZ_SG_HEADER;
 542                if (count > old_hdr->reply_len)
 543                        count = old_hdr->reply_len;
 544                if (count > SZ_SG_HEADER) {
 545                        if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 546                                retval = -EFAULT;
 547                                goto free_old_hdr;
 548                        }
 549                }
 550        } else
 551                count = (old_hdr->result == 0) ? 0 : -EIO;
 552        sg_finish_rem_req(srp);
 553        sg_remove_request(sfp, srp);
 554        retval = count;
 555free_old_hdr:
 556        kfree(old_hdr);
 557        return retval;
 558}
 559
 560static ssize_t
 561sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 562{
 563        sg_io_hdr_t *hp = &srp->header;
 564        int err = 0, err2;
 565        int len;
 566
 567        if (in_compat_syscall()) {
 568                if (count < sizeof(struct compat_sg_io_hdr)) {
 569                        err = -EINVAL;
 570                        goto err_out;
 571                }
 572        } else if (count < SZ_SG_IO_HDR) {
 573                err = -EINVAL;
 574                goto err_out;
 575        }
 576        hp->sb_len_wr = 0;
 577        if ((hp->mx_sb_len > 0) && hp->sbp) {
 578                if ((CHECK_CONDITION & hp->masked_status) ||
 579                    (srp->sense_b[0] & 0x70) == 0x70) {
 580                        int sb_len = SCSI_SENSE_BUFFERSIZE;
 581                        sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 582                        len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 583                        len = (len > sb_len) ? sb_len : len;
 584                        if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 585                                err = -EFAULT;
 586                                goto err_out;
 587                        }
 588                        hp->driver_status = DRIVER_SENSE;
 589                        hp->sb_len_wr = len;
 590                }
 591        }
 592        if (hp->masked_status || hp->host_status || hp->driver_status)
 593                hp->info |= SG_INFO_CHECK;
 594        err = put_sg_io_hdr(hp, buf);
 595err_out:
 596        err2 = sg_finish_rem_req(srp);
 597        sg_remove_request(sfp, srp);
 598        return err ? : err2 ? : count;
 599}
 600
 601static ssize_t
 602sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 603{
 604        int mxsize, cmd_size, k;
 605        int input_size, blocking;
 606        unsigned char opcode;
 607        Sg_device *sdp;
 608        Sg_fd *sfp;
 609        Sg_request *srp;
 610        struct sg_header old_hdr;
 611        sg_io_hdr_t *hp;
 612        unsigned char cmnd[SG_MAX_CDB_SIZE];
 613        int retval;
 614
 615        retval = sg_check_file_access(filp, __func__);
 616        if (retval)
 617                return retval;
 618
 619        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 620                return -ENXIO;
 621        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 622                                      "sg_write: count=%d\n", (int) count));
 623        if (atomic_read(&sdp->detaching))
 624                return -ENODEV;
 625        if (!((filp->f_flags & O_NONBLOCK) ||
 626              scsi_block_when_processing_errors(sdp->device)))
 627                return -ENXIO;
 628
 629        if (count < SZ_SG_HEADER)
 630                return -EIO;
 631        if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 632                return -EFAULT;
 633        blocking = !(filp->f_flags & O_NONBLOCK);
 634        if (old_hdr.reply_len < 0)
 635                return sg_new_write(sfp, filp, buf, count,
 636                                    blocking, 0, 0, NULL);
 637        if (count < (SZ_SG_HEADER + 6))
 638                return -EIO;    /* The minimum scsi command length is 6 bytes. */
 639
 640        buf += SZ_SG_HEADER;
 641        if (get_user(opcode, buf))
 642                return -EFAULT;
 643
 644        if (!(srp = sg_add_request(sfp))) {
 645                SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 646                                              "sg_write: queue full\n"));
 647                return -EDOM;
 648        }
 649        mutex_lock(&sfp->f_mutex);
 650        if (sfp->next_cmd_len > 0) {
 651                cmd_size = sfp->next_cmd_len;
 652                sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 653        } else {
 654                cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 655                if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 656                        cmd_size = 12;
 657        }
 658        mutex_unlock(&sfp->f_mutex);
 659        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 660                "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 661/* Determine buffer size.  */
 662        input_size = count - cmd_size;
 663        mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 664        mxsize -= SZ_SG_HEADER;
 665        input_size -= SZ_SG_HEADER;
 666        if (input_size < 0) {
 667                sg_remove_request(sfp, srp);
 668                return -EIO;    /* User did not pass enough bytes for this command. */
 669        }
 670        hp = &srp->header;
 671        hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 672        hp->cmd_len = (unsigned char) cmd_size;
 673        hp->iovec_count = 0;
 674        hp->mx_sb_len = 0;
 675        if (input_size > 0)
 676                hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 677                    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 678        else
 679                hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 680        hp->dxfer_len = mxsize;
 681        if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 682            (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 683                hp->dxferp = (char __user *)buf + cmd_size;
 684        else
 685                hp->dxferp = NULL;
 686        hp->sbp = NULL;
 687        hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 688        hp->flags = input_size; /* structure abuse ... */
 689        hp->pack_id = old_hdr.pack_id;
 690        hp->usr_ptr = NULL;
 691        if (copy_from_user(cmnd, buf, cmd_size)) {
 692                sg_remove_request(sfp, srp);
 693                return -EFAULT;
 694        }
 695        /*
 696         * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 697         * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 698         * is a non-zero input_size, so emit a warning.
 699         */
 700        if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 701                printk_ratelimited(KERN_WARNING
 702                                   "sg_write: data in/out %d/%d bytes "
 703                                   "for SCSI command 0x%x-- guessing "
 704                                   "data in;\n   program %s not setting "
 705                                   "count and/or reply_len properly\n",
 706                                   old_hdr.reply_len - (int)SZ_SG_HEADER,
 707                                   input_size, (unsigned int) cmnd[0],
 708                                   current->comm);
 709        }
 710        k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 711        return (k < 0) ? k : count;
 712}
 713
 714static ssize_t
 715sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 716                 size_t count, int blocking, int read_only, int sg_io_owned,
 717                 Sg_request **o_srp)
 718{
 719        int k;
 720        Sg_request *srp;
 721        sg_io_hdr_t *hp;
 722        unsigned char cmnd[SG_MAX_CDB_SIZE];
 723        int timeout;
 724        unsigned long ul_timeout;
 725
 726        if (count < SZ_SG_IO_HDR)
 727                return -EINVAL;
 728
 729        sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 730        if (!(srp = sg_add_request(sfp))) {
 731                SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 732                                              "sg_new_write: queue full\n"));
 733                return -EDOM;
 734        }
 735        srp->sg_io_owned = sg_io_owned;
 736        hp = &srp->header;
 737        if (get_sg_io_hdr(hp, buf)) {
 738                sg_remove_request(sfp, srp);
 739                return -EFAULT;
 740        }
 741        if (hp->interface_id != 'S') {
 742                sg_remove_request(sfp, srp);
 743                return -ENOSYS;
 744        }
 745        if (hp->flags & SG_FLAG_MMAP_IO) {
 746                if (hp->dxfer_len > sfp->reserve.bufflen) {
 747                        sg_remove_request(sfp, srp);
 748                        return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 749                }
 750                if (hp->flags & SG_FLAG_DIRECT_IO) {
 751                        sg_remove_request(sfp, srp);
 752                        return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 753                }
 754                if (sfp->res_in_use) {
 755                        sg_remove_request(sfp, srp);
 756                        return -EBUSY;  /* reserve buffer already being used */
 757                }
 758        }
 759        ul_timeout = msecs_to_jiffies(srp->header.timeout);
 760        timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 761        if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 762                sg_remove_request(sfp, srp);
 763                return -EMSGSIZE;
 764        }
 765        if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 766                sg_remove_request(sfp, srp);
 767                return -EFAULT;
 768        }
 769        if (read_only && sg_allow_access(file, cmnd)) {
 770                sg_remove_request(sfp, srp);
 771                return -EPERM;
 772        }
 773        k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 774        if (k < 0)
 775                return k;
 776        if (o_srp)
 777                *o_srp = srp;
 778        return count;
 779}
 780
 781static int
 782sg_common_write(Sg_fd * sfp, Sg_request * srp,
 783                unsigned char *cmnd, int timeout, int blocking)
 784{
 785        int k, at_head;
 786        Sg_device *sdp = sfp->parentdp;
 787        sg_io_hdr_t *hp = &srp->header;
 788
 789        srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 790        hp->status = 0;
 791        hp->masked_status = 0;
 792        hp->msg_status = 0;
 793        hp->info = 0;
 794        hp->host_status = 0;
 795        hp->driver_status = 0;
 796        hp->resid = 0;
 797        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 798                        "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 799                        (int) cmnd[0], (int) hp->cmd_len));
 800
 801        if (hp->dxfer_len >= SZ_256M) {
 802                sg_remove_request(sfp, srp);
 803                return -EINVAL;
 804        }
 805
 806        k = sg_start_req(srp, cmnd);
 807        if (k) {
 808                SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 809                        "sg_common_write: start_req err=%d\n", k));
 810                sg_finish_rem_req(srp);
 811                sg_remove_request(sfp, srp);
 812                return k;       /* probably out of space --> ENOMEM */
 813        }
 814        if (atomic_read(&sdp->detaching)) {
 815                if (srp->bio) {
 816                        scsi_req_free_cmd(scsi_req(srp->rq));
 817                        blk_put_request(srp->rq);
 818                        srp->rq = NULL;
 819                }
 820
 821                sg_finish_rem_req(srp);
 822                sg_remove_request(sfp, srp);
 823                return -ENODEV;
 824        }
 825
 826        hp->duration = jiffies_to_msecs(jiffies);
 827        if (hp->interface_id != '\0' && /* v3 (or later) interface */
 828            (SG_FLAG_Q_AT_TAIL & hp->flags))
 829                at_head = 0;
 830        else
 831                at_head = 1;
 832
 833        srp->rq->timeout = timeout;
 834        kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 835        blk_execute_rq_nowait(sdp->disk, srp->rq, at_head, sg_rq_end_io);
 836        return 0;
 837}
 838
 839static int srp_done(Sg_fd *sfp, Sg_request *srp)
 840{
 841        unsigned long flags;
 842        int ret;
 843
 844        read_lock_irqsave(&sfp->rq_list_lock, flags);
 845        ret = srp->done;
 846        read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 847        return ret;
 848}
 849
 850static int max_sectors_bytes(struct request_queue *q)
 851{
 852        unsigned int max_sectors = queue_max_sectors(q);
 853
 854        max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 855
 856        return max_sectors << 9;
 857}
 858
 859static void
 860sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 861{
 862        Sg_request *srp;
 863        int val;
 864        unsigned int ms;
 865
 866        val = 0;
 867        list_for_each_entry(srp, &sfp->rq_list, entry) {
 868                if (val >= SG_MAX_QUEUE)
 869                        break;
 870                rinfo[val].req_state = srp->done + 1;
 871                rinfo[val].problem =
 872                        srp->header.masked_status &
 873                        srp->header.host_status &
 874                        srp->header.driver_status;
 875                if (srp->done)
 876                        rinfo[val].duration =
 877                                srp->header.duration;
 878                else {
 879                        ms = jiffies_to_msecs(jiffies);
 880                        rinfo[val].duration =
 881                                (ms > srp->header.duration) ?
 882                                (ms - srp->header.duration) : 0;
 883                }
 884                rinfo[val].orphan = srp->orphan;
 885                rinfo[val].sg_io_owned = srp->sg_io_owned;
 886                rinfo[val].pack_id = srp->header.pack_id;
 887                rinfo[val].usr_ptr = srp->header.usr_ptr;
 888                val++;
 889        }
 890}
 891
 892#ifdef CONFIG_COMPAT
 893struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
 894        char req_state;
 895        char orphan;
 896        char sg_io_owned;
 897        char problem;
 898        int pack_id;
 899        compat_uptr_t usr_ptr;
 900        unsigned int duration;
 901        int unused;
 902};
 903
 904static int put_compat_request_table(struct compat_sg_req_info __user *o,
 905                                    struct sg_req_info *rinfo)
 906{
 907        int i;
 908        for (i = 0; i < SG_MAX_QUEUE; i++) {
 909                if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
 910                    put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
 911                    put_user(rinfo[i].duration, &o[i].duration) ||
 912                    put_user(rinfo[i].unused, &o[i].unused))
 913                        return -EFAULT;
 914        }
 915        return 0;
 916}
 917#endif
 918
 919static long
 920sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
 921                unsigned int cmd_in, void __user *p)
 922{
 923        int __user *ip = p;
 924        int result, val, read_only;
 925        Sg_request *srp;
 926        unsigned long iflags;
 927
 928        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 929                                   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 930        read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 931
 932        switch (cmd_in) {
 933        case SG_IO:
 934                if (atomic_read(&sdp->detaching))
 935                        return -ENODEV;
 936                if (!scsi_block_when_processing_errors(sdp->device))
 937                        return -ENXIO;
 938                result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 939                                 1, read_only, 1, &srp);
 940                if (result < 0)
 941                        return result;
 942                result = wait_event_interruptible(sfp->read_wait,
 943                        (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 944                if (atomic_read(&sdp->detaching))
 945                        return -ENODEV;
 946                write_lock_irq(&sfp->rq_list_lock);
 947                if (srp->done) {
 948                        srp->done = 2;
 949                        write_unlock_irq(&sfp->rq_list_lock);
 950                        result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 951                        return (result < 0) ? result : 0;
 952                }
 953                srp->orphan = 1;
 954                write_unlock_irq(&sfp->rq_list_lock);
 955                return result;  /* -ERESTARTSYS because signal hit process */
 956        case SG_SET_TIMEOUT:
 957                result = get_user(val, ip);
 958                if (result)
 959                        return result;
 960                if (val < 0)
 961                        return -EIO;
 962                if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 963                        val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 964                                    INT_MAX);
 965                sfp->timeout_user = val;
 966                sfp->timeout = mult_frac(val, HZ, USER_HZ);
 967
 968                return 0;
 969        case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 970                                /* strange ..., for backward compatibility */
 971                return sfp->timeout_user;
 972        case SG_SET_FORCE_LOW_DMA:
 973                /*
 974                 * N.B. This ioctl never worked properly, but failed to
 975                 * return an error value. So returning '0' to keep compability
 976                 * with legacy applications.
 977                 */
 978                return 0;
 979        case SG_GET_LOW_DMA:
 980                return put_user(0, ip);
 981        case SG_GET_SCSI_ID:
 982                {
 983                        sg_scsi_id_t v;
 984
 985                        if (atomic_read(&sdp->detaching))
 986                                return -ENODEV;
 987                        memset(&v, 0, sizeof(v));
 988                        v.host_no = sdp->device->host->host_no;
 989                        v.channel = sdp->device->channel;
 990                        v.scsi_id = sdp->device->id;
 991                        v.lun = sdp->device->lun;
 992                        v.scsi_type = sdp->device->type;
 993                        v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
 994                        v.d_queue_depth = sdp->device->queue_depth;
 995                        if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
 996                                return -EFAULT;
 997                        return 0;
 998                }
 999        case SG_SET_FORCE_PACK_ID:
1000                result = get_user(val, ip);
1001                if (result)
1002                        return result;
1003                sfp->force_packid = val ? 1 : 0;
1004                return 0;
1005        case SG_GET_PACK_ID:
1006                read_lock_irqsave(&sfp->rq_list_lock, iflags);
1007                list_for_each_entry(srp, &sfp->rq_list, entry) {
1008                        if ((1 == srp->done) && (!srp->sg_io_owned)) {
1009                                read_unlock_irqrestore(&sfp->rq_list_lock,
1010                                                       iflags);
1011                                return put_user(srp->header.pack_id, ip);
1012                        }
1013                }
1014                read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1015                return put_user(-1, ip);
1016        case SG_GET_NUM_WAITING:
1017                read_lock_irqsave(&sfp->rq_list_lock, iflags);
1018                val = 0;
1019                list_for_each_entry(srp, &sfp->rq_list, entry) {
1020                        if ((1 == srp->done) && (!srp->sg_io_owned))
1021                                ++val;
1022                }
1023                read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1024                return put_user(val, ip);
1025        case SG_GET_SG_TABLESIZE:
1026                return put_user(sdp->sg_tablesize, ip);
1027        case SG_SET_RESERVED_SIZE:
1028                result = get_user(val, ip);
1029                if (result)
1030                        return result;
1031                if (val < 0)
1032                        return -EINVAL;
1033                val = min_t(int, val,
1034                            max_sectors_bytes(sdp->device->request_queue));
1035                mutex_lock(&sfp->f_mutex);
1036                if (val != sfp->reserve.bufflen) {
1037                        if (sfp->mmap_called ||
1038                            sfp->res_in_use) {
1039                                mutex_unlock(&sfp->f_mutex);
1040                                return -EBUSY;
1041                        }
1042
1043                        sg_remove_scat(sfp, &sfp->reserve);
1044                        sg_build_reserve(sfp, val);
1045                }
1046                mutex_unlock(&sfp->f_mutex);
1047                return 0;
1048        case SG_GET_RESERVED_SIZE:
1049                val = min_t(int, sfp->reserve.bufflen,
1050                            max_sectors_bytes(sdp->device->request_queue));
1051                return put_user(val, ip);
1052        case SG_SET_COMMAND_Q:
1053                result = get_user(val, ip);
1054                if (result)
1055                        return result;
1056                sfp->cmd_q = val ? 1 : 0;
1057                return 0;
1058        case SG_GET_COMMAND_Q:
1059                return put_user((int) sfp->cmd_q, ip);
1060        case SG_SET_KEEP_ORPHAN:
1061                result = get_user(val, ip);
1062                if (result)
1063                        return result;
1064                sfp->keep_orphan = val;
1065                return 0;
1066        case SG_GET_KEEP_ORPHAN:
1067                return put_user((int) sfp->keep_orphan, ip);
1068        case SG_NEXT_CMD_LEN:
1069                result = get_user(val, ip);
1070                if (result)
1071                        return result;
1072                if (val > SG_MAX_CDB_SIZE)
1073                        return -ENOMEM;
1074                sfp->next_cmd_len = (val > 0) ? val : 0;
1075                return 0;
1076        case SG_GET_VERSION_NUM:
1077                return put_user(sg_version_num, ip);
1078        case SG_GET_ACCESS_COUNT:
1079                /* faked - we don't have a real access count anymore */
1080                val = (sdp->device ? 1 : 0);
1081                return put_user(val, ip);
1082        case SG_GET_REQUEST_TABLE:
1083                {
1084                        sg_req_info_t *rinfo;
1085
1086                        rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1087                                        GFP_KERNEL);
1088                        if (!rinfo)
1089                                return -ENOMEM;
1090                        read_lock_irqsave(&sfp->rq_list_lock, iflags);
1091                        sg_fill_request_table(sfp, rinfo);
1092                        read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1093        #ifdef CONFIG_COMPAT
1094                        if (in_compat_syscall())
1095                                result = put_compat_request_table(p, rinfo);
1096                        else
1097        #endif
1098                                result = copy_to_user(p, rinfo,
1099                                                      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1100                        result = result ? -EFAULT : 0;
1101                        kfree(rinfo);
1102                        return result;
1103                }
1104        case SG_EMULATED_HOST:
1105                if (atomic_read(&sdp->detaching))
1106                        return -ENODEV;
1107                return put_user(sdp->device->host->hostt->emulated, ip);
1108        case SCSI_IOCTL_SEND_COMMAND:
1109                if (atomic_read(&sdp->detaching))
1110                        return -ENODEV;
1111                return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1112        case SG_SET_DEBUG:
1113                result = get_user(val, ip);
1114                if (result)
1115                        return result;
1116                sdp->sgdebug = (char) val;
1117                return 0;
1118        case BLKSECTGET:
1119                return put_user(max_sectors_bytes(sdp->device->request_queue),
1120                                ip);
1121        case BLKTRACESETUP:
1122                return blk_trace_setup(sdp->device->request_queue,
1123                                       sdp->disk->disk_name,
1124                                       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1125                                       NULL, p);
1126        case BLKTRACESTART:
1127                return blk_trace_startstop(sdp->device->request_queue, 1);
1128        case BLKTRACESTOP:
1129                return blk_trace_startstop(sdp->device->request_queue, 0);
1130        case BLKTRACETEARDOWN:
1131                return blk_trace_remove(sdp->device->request_queue);
1132        case SCSI_IOCTL_GET_IDLUN:
1133        case SCSI_IOCTL_GET_BUS_NUMBER:
1134        case SCSI_IOCTL_PROBE_HOST:
1135        case SG_GET_TRANSFORM:
1136        case SG_SCSI_RESET:
1137                if (atomic_read(&sdp->detaching))
1138                        return -ENODEV;
1139                break;
1140        default:
1141                if (read_only)
1142                        return -EPERM;  /* don't know so take safe approach */
1143                break;
1144        }
1145
1146        result = scsi_ioctl_block_when_processing_errors(sdp->device,
1147                        cmd_in, filp->f_flags & O_NDELAY);
1148        if (result)
1149                return result;
1150
1151        return -ENOIOCTLCMD;
1152}
1153
1154static long
1155sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1156{
1157        void __user *p = (void __user *)arg;
1158        Sg_device *sdp;
1159        Sg_fd *sfp;
1160        int ret;
1161
1162        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1163                return -ENXIO;
1164
1165        ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1166        if (ret != -ENOIOCTLCMD)
1167                return ret;
1168
1169        return scsi_ioctl(sdp->device, cmd_in, p);
1170}
1171
1172#ifdef CONFIG_COMPAT
1173static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1174{
1175        void __user *p = compat_ptr(arg);
1176        Sg_device *sdp;
1177        Sg_fd *sfp;
1178        int ret;
1179
1180        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1181                return -ENXIO;
1182
1183        ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1184        if (ret != -ENOIOCTLCMD)
1185                return ret;
1186
1187        return scsi_compat_ioctl(sdp->device, cmd_in, p);
1188}
1189#endif
1190
1191static __poll_t
1192sg_poll(struct file *filp, poll_table * wait)
1193{
1194        __poll_t res = 0;
1195        Sg_device *sdp;
1196        Sg_fd *sfp;
1197        Sg_request *srp;
1198        int count = 0;
1199        unsigned long iflags;
1200
1201        sfp = filp->private_data;
1202        if (!sfp)
1203                return EPOLLERR;
1204        sdp = sfp->parentdp;
1205        if (!sdp)
1206                return EPOLLERR;
1207        poll_wait(filp, &sfp->read_wait, wait);
1208        read_lock_irqsave(&sfp->rq_list_lock, iflags);
1209        list_for_each_entry(srp, &sfp->rq_list, entry) {
1210                /* if any read waiting, flag it */
1211                if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1212                        res = EPOLLIN | EPOLLRDNORM;
1213                ++count;
1214        }
1215        read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1216
1217        if (atomic_read(&sdp->detaching))
1218                res |= EPOLLHUP;
1219        else if (!sfp->cmd_q) {
1220                if (0 == count)
1221                        res |= EPOLLOUT | EPOLLWRNORM;
1222        } else if (count < SG_MAX_QUEUE)
1223                res |= EPOLLOUT | EPOLLWRNORM;
1224        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1225                                      "sg_poll: res=0x%x\n", (__force u32) res));
1226        return res;
1227}
1228
1229static int
1230sg_fasync(int fd, struct file *filp, int mode)
1231{
1232        Sg_device *sdp;
1233        Sg_fd *sfp;
1234
1235        if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1236                return -ENXIO;
1237        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1238                                      "sg_fasync: mode=%d\n", mode));
1239
1240        return fasync_helper(fd, filp, mode, &sfp->async_qp);
1241}
1242
1243static vm_fault_t
1244sg_vma_fault(struct vm_fault *vmf)
1245{
1246        struct vm_area_struct *vma = vmf->vma;
1247        Sg_fd *sfp;
1248        unsigned long offset, len, sa;
1249        Sg_scatter_hold *rsv_schp;
1250        int k, length;
1251
1252        if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1253                return VM_FAULT_SIGBUS;
1254        rsv_schp = &sfp->reserve;
1255        offset = vmf->pgoff << PAGE_SHIFT;
1256        if (offset >= rsv_schp->bufflen)
1257                return VM_FAULT_SIGBUS;
1258        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1259                                      "sg_vma_fault: offset=%lu, scatg=%d\n",
1260                                      offset, rsv_schp->k_use_sg));
1261        sa = vma->vm_start;
1262        length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1263        for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1264                len = vma->vm_end - sa;
1265                len = (len < length) ? len : length;
1266                if (offset < len) {
1267                        struct page *page = nth_page(rsv_schp->pages[k],
1268                                                     offset >> PAGE_SHIFT);
1269                        get_page(page); /* increment page count */
1270                        vmf->page = page;
1271                        return 0; /* success */
1272                }
1273                sa += len;
1274                offset -= len;
1275        }
1276
1277        return VM_FAULT_SIGBUS;
1278}
1279
1280static const struct vm_operations_struct sg_mmap_vm_ops = {
1281        .fault = sg_vma_fault,
1282};
1283
1284static int
1285sg_mmap(struct file *filp, struct vm_area_struct *vma)
1286{
1287        Sg_fd *sfp;
1288        unsigned long req_sz, len, sa;
1289        Sg_scatter_hold *rsv_schp;
1290        int k, length;
1291        int ret = 0;
1292
1293        if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1294                return -ENXIO;
1295        req_sz = vma->vm_end - vma->vm_start;
1296        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1297                                      "sg_mmap starting, vm_start=%p, len=%d\n",
1298                                      (void *) vma->vm_start, (int) req_sz));
1299        if (vma->vm_pgoff)
1300                return -EINVAL; /* want no offset */
1301        rsv_schp = &sfp->reserve;
1302        mutex_lock(&sfp->f_mutex);
1303        if (req_sz > rsv_schp->bufflen) {
1304                ret = -ENOMEM;  /* cannot map more than reserved buffer */
1305                goto out;
1306        }
1307
1308        sa = vma->vm_start;
1309        length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1310        for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1311                len = vma->vm_end - sa;
1312                len = (len < length) ? len : length;
1313                sa += len;
1314        }
1315
1316        sfp->mmap_called = 1;
1317        vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1318        vma->vm_private_data = sfp;
1319        vma->vm_ops = &sg_mmap_vm_ops;
1320out:
1321        mutex_unlock(&sfp->f_mutex);
1322        return ret;
1323}
1324
1325static void
1326sg_rq_end_io_usercontext(struct work_struct *work)
1327{
1328        struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1329        struct sg_fd *sfp = srp->parentfp;
1330
1331        sg_finish_rem_req(srp);
1332        sg_remove_request(sfp, srp);
1333        kref_put(&sfp->f_ref, sg_remove_sfp);
1334}
1335
1336/*
1337 * This function is a "bottom half" handler that is called by the mid
1338 * level when a command is completed (or has failed).
1339 */
1340static void
1341sg_rq_end_io(struct request *rq, blk_status_t status)
1342{
1343        struct sg_request *srp = rq->end_io_data;
1344        struct scsi_request *req = scsi_req(rq);
1345        Sg_device *sdp;
1346        Sg_fd *sfp;
1347        unsigned long iflags;
1348        unsigned int ms;
1349        char *sense;
1350        int result, resid, done = 1;
1351
1352        if (WARN_ON(srp->done != 0))
1353                return;
1354
1355        sfp = srp->parentfp;
1356        if (WARN_ON(sfp == NULL))
1357                return;
1358
1359        sdp = sfp->parentdp;
1360        if (unlikely(atomic_read(&sdp->detaching)))
1361                pr_info("%s: device detaching\n", __func__);
1362
1363        sense = req->sense;
1364        result = req->result;
1365        resid = req->resid_len;
1366
1367        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1368                                      "sg_cmd_done: pack_id=%d, res=0x%x\n",
1369                                      srp->header.pack_id, result));
1370        srp->header.resid = resid;
1371        ms = jiffies_to_msecs(jiffies);
1372        srp->header.duration = (ms > srp->header.duration) ?
1373                                (ms - srp->header.duration) : 0;
1374        if (0 != result) {
1375                struct scsi_sense_hdr sshdr;
1376
1377                srp->header.status = 0xff & result;
1378                srp->header.masked_status = status_byte(result);
1379                srp->header.msg_status = COMMAND_COMPLETE;
1380                srp->header.host_status = host_byte(result);
1381                srp->header.driver_status = driver_byte(result);
1382                if ((sdp->sgdebug > 0) &&
1383                    ((CHECK_CONDITION == srp->header.masked_status) ||
1384                     (COMMAND_TERMINATED == srp->header.masked_status)))
1385                        __scsi_print_sense(sdp->device, __func__, sense,
1386                                           SCSI_SENSE_BUFFERSIZE);
1387
1388                /* Following if statement is a patch supplied by Eric Youngdale */
1389                if (driver_byte(result) != 0
1390                    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1391                    && !scsi_sense_is_deferred(&sshdr)
1392                    && sshdr.sense_key == UNIT_ATTENTION
1393                    && sdp->device->removable) {
1394                        /* Detected possible disc change. Set the bit - this */
1395                        /* may be used if there are filesystems using this device */
1396                        sdp->device->changed = 1;
1397                }
1398        }
1399
1400        if (req->sense_len)
1401                memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1402
1403        /* Rely on write phase to clean out srp status values, so no "else" */
1404
1405        /*
1406         * Free the request as soon as it is complete so that its resources
1407         * can be reused without waiting for userspace to read() the
1408         * result.  But keep the associated bio (if any) around until
1409         * blk_rq_unmap_user() can be called from user context.
1410         */
1411        srp->rq = NULL;
1412        scsi_req_free_cmd(scsi_req(rq));
1413        blk_put_request(rq);
1414
1415        write_lock_irqsave(&sfp->rq_list_lock, iflags);
1416        if (unlikely(srp->orphan)) {
1417                if (sfp->keep_orphan)
1418                        srp->sg_io_owned = 0;
1419                else
1420                        done = 0;
1421        }
1422        srp->done = done;
1423        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1424
1425        if (likely(done)) {
1426                /* Now wake up any sg_read() that is waiting for this
1427                 * packet.
1428                 */
1429                wake_up_interruptible(&sfp->read_wait);
1430                kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1431                kref_put(&sfp->f_ref, sg_remove_sfp);
1432        } else {
1433                INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1434                schedule_work(&srp->ew.work);
1435        }
1436}
1437
1438static const struct file_operations sg_fops = {
1439        .owner = THIS_MODULE,
1440        .read = sg_read,
1441        .write = sg_write,
1442        .poll = sg_poll,
1443        .unlocked_ioctl = sg_ioctl,
1444#ifdef CONFIG_COMPAT
1445        .compat_ioctl = sg_compat_ioctl,
1446#endif
1447        .open = sg_open,
1448        .mmap = sg_mmap,
1449        .release = sg_release,
1450        .fasync = sg_fasync,
1451        .llseek = no_llseek,
1452};
1453
1454static struct class *sg_sysfs_class;
1455
1456static int sg_sysfs_valid = 0;
1457
1458static Sg_device *
1459sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1460{
1461        struct request_queue *q = scsidp->request_queue;
1462        Sg_device *sdp;
1463        unsigned long iflags;
1464        int error;
1465        u32 k;
1466
1467        sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1468        if (!sdp) {
1469                sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1470                            "failure\n", __func__);
1471                return ERR_PTR(-ENOMEM);
1472        }
1473
1474        idr_preload(GFP_KERNEL);
1475        write_lock_irqsave(&sg_index_lock, iflags);
1476
1477        error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1478        if (error < 0) {
1479                if (error == -ENOSPC) {
1480                        sdev_printk(KERN_WARNING, scsidp,
1481                                    "Unable to attach sg device type=%d, minor number exceeds %d\n",
1482                                    scsidp->type, SG_MAX_DEVS - 1);
1483                        error = -ENODEV;
1484                } else {
1485                        sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1486                                    "allocation Sg_device failure: %d\n",
1487                                    __func__, error);
1488                }
1489                goto out_unlock;
1490        }
1491        k = error;
1492
1493        SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1494                                        "sg_alloc: dev=%d \n", k));
1495        sprintf(disk->disk_name, "sg%d", k);
1496        disk->first_minor = k;
1497        sdp->disk = disk;
1498        sdp->device = scsidp;
1499        mutex_init(&sdp->open_rel_lock);
1500        INIT_LIST_HEAD(&sdp->sfds);
1501        init_waitqueue_head(&sdp->open_wait);
1502        atomic_set(&sdp->detaching, 0);
1503        rwlock_init(&sdp->sfd_lock);
1504        sdp->sg_tablesize = queue_max_segments(q);
1505        sdp->index = k;
1506        kref_init(&sdp->d_ref);
1507        error = 0;
1508
1509out_unlock:
1510        write_unlock_irqrestore(&sg_index_lock, iflags);
1511        idr_preload_end();
1512
1513        if (error) {
1514                kfree(sdp);
1515                return ERR_PTR(error);
1516        }
1517        return sdp;
1518}
1519
1520static int
1521sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1522{
1523        struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1524        struct gendisk *disk;
1525        Sg_device *sdp = NULL;
1526        struct cdev * cdev = NULL;
1527        int error;
1528        unsigned long iflags;
1529
1530        disk = alloc_disk(1);
1531        if (!disk) {
1532                pr_warn("%s: alloc_disk failed\n", __func__);
1533                return -ENOMEM;
1534        }
1535        disk->major = SCSI_GENERIC_MAJOR;
1536
1537        error = -ENOMEM;
1538        cdev = cdev_alloc();
1539        if (!cdev) {
1540                pr_warn("%s: cdev_alloc failed\n", __func__);
1541                goto out;
1542        }
1543        cdev->owner = THIS_MODULE;
1544        cdev->ops = &sg_fops;
1545
1546        sdp = sg_alloc(disk, scsidp);
1547        if (IS_ERR(sdp)) {
1548                pr_warn("%s: sg_alloc failed\n", __func__);
1549                error = PTR_ERR(sdp);
1550                goto out;
1551        }
1552
1553        error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1554        if (error)
1555                goto cdev_add_err;
1556
1557        sdp->cdev = cdev;
1558        if (sg_sysfs_valid) {
1559                struct device *sg_class_member;
1560
1561                sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1562                                                MKDEV(SCSI_GENERIC_MAJOR,
1563                                                      sdp->index),
1564                                                sdp, "%s", disk->disk_name);
1565                if (IS_ERR(sg_class_member)) {
1566                        pr_err("%s: device_create failed\n", __func__);
1567                        error = PTR_ERR(sg_class_member);
1568                        goto cdev_add_err;
1569                }
1570                error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1571                                          &sg_class_member->kobj, "generic");
1572                if (error)
1573                        pr_err("%s: unable to make symlink 'generic' back "
1574                               "to sg%d\n", __func__, sdp->index);
1575        } else
1576                pr_warn("%s: sg_sys Invalid\n", __func__);
1577
1578        sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1579                    "type %d\n", sdp->index, scsidp->type);
1580
1581        dev_set_drvdata(cl_dev, sdp);
1582
1583        return 0;
1584
1585cdev_add_err:
1586        write_lock_irqsave(&sg_index_lock, iflags);
1587        idr_remove(&sg_index_idr, sdp->index);
1588        write_unlock_irqrestore(&sg_index_lock, iflags);
1589        kfree(sdp);
1590
1591out:
1592        put_disk(disk);
1593        if (cdev)
1594                cdev_del(cdev);
1595        return error;
1596}
1597
1598static void
1599sg_device_destroy(struct kref *kref)
1600{
1601        struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1602        unsigned long flags;
1603
1604        /* CAUTION!  Note that the device can still be found via idr_find()
1605         * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1606         * any other cleanup.
1607         */
1608
1609        write_lock_irqsave(&sg_index_lock, flags);
1610        idr_remove(&sg_index_idr, sdp->index);
1611        write_unlock_irqrestore(&sg_index_lock, flags);
1612
1613        SCSI_LOG_TIMEOUT(3,
1614                sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1615
1616        put_disk(sdp->disk);
1617        kfree(sdp);
1618}
1619
1620static void
1621sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1622{
1623        struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1624        Sg_device *sdp = dev_get_drvdata(cl_dev);
1625        unsigned long iflags;
1626        Sg_fd *sfp;
1627        int val;
1628
1629        if (!sdp)
1630                return;
1631        /* want sdp->detaching non-zero as soon as possible */
1632        val = atomic_inc_return(&sdp->detaching);
1633        if (val > 1)
1634                return; /* only want to do following once per device */
1635
1636        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1637                                      "%s\n", __func__));
1638
1639        read_lock_irqsave(&sdp->sfd_lock, iflags);
1640        list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1641                wake_up_interruptible_all(&sfp->read_wait);
1642                kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1643        }
1644        wake_up_interruptible_all(&sdp->open_wait);
1645        read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1646
1647        sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1648        device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1649        cdev_del(sdp->cdev);
1650        sdp->cdev = NULL;
1651
1652        kref_put(&sdp->d_ref, sg_device_destroy);
1653}
1654
1655module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1656module_param_named(def_reserved_size, def_reserved_size, int,
1657                   S_IRUGO | S_IWUSR);
1658module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1659
1660MODULE_AUTHOR("Douglas Gilbert");
1661MODULE_DESCRIPTION("SCSI generic (sg) driver");
1662MODULE_LICENSE("GPL");
1663MODULE_VERSION(SG_VERSION_STR);
1664MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1665
1666MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1667                "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1668MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1669MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1670
1671static int __init
1672init_sg(void)
1673{
1674        int rc;
1675
1676        if (scatter_elem_sz < PAGE_SIZE) {
1677                scatter_elem_sz = PAGE_SIZE;
1678                scatter_elem_sz_prev = scatter_elem_sz;
1679        }
1680        if (def_reserved_size >= 0)
1681                sg_big_buff = def_reserved_size;
1682        else
1683                def_reserved_size = sg_big_buff;
1684
1685        rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1686                                    SG_MAX_DEVS, "sg");
1687        if (rc)
1688                return rc;
1689        sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1690        if ( IS_ERR(sg_sysfs_class) ) {
1691                rc = PTR_ERR(sg_sysfs_class);
1692                goto err_out;
1693        }
1694        sg_sysfs_valid = 1;
1695        rc = scsi_register_interface(&sg_interface);
1696        if (0 == rc) {
1697#ifdef CONFIG_SCSI_PROC_FS
1698                sg_proc_init();
1699#endif                          /* CONFIG_SCSI_PROC_FS */
1700                return 0;
1701        }
1702        class_destroy(sg_sysfs_class);
1703err_out:
1704        unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1705        return rc;
1706}
1707
1708static void __exit
1709exit_sg(void)
1710{
1711#ifdef CONFIG_SCSI_PROC_FS
1712        remove_proc_subtree("scsi/sg", NULL);
1713#endif                          /* CONFIG_SCSI_PROC_FS */
1714        scsi_unregister_interface(&sg_interface);
1715        class_destroy(sg_sysfs_class);
1716        sg_sysfs_valid = 0;
1717        unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1718                                 SG_MAX_DEVS);
1719        idr_destroy(&sg_index_idr);
1720}
1721
1722static int
1723sg_start_req(Sg_request *srp, unsigned char *cmd)
1724{
1725        int res;
1726        struct request *rq;
1727        struct scsi_request *req;
1728        Sg_fd *sfp = srp->parentfp;
1729        sg_io_hdr_t *hp = &srp->header;
1730        int dxfer_len = (int) hp->dxfer_len;
1731        int dxfer_dir = hp->dxfer_direction;
1732        unsigned int iov_count = hp->iovec_count;
1733        Sg_scatter_hold *req_schp = &srp->data;
1734        Sg_scatter_hold *rsv_schp = &sfp->reserve;
1735        struct request_queue *q = sfp->parentdp->device->request_queue;
1736        struct rq_map_data *md, map_data;
1737        int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1738        unsigned char *long_cmdp = NULL;
1739
1740        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1741                                      "sg_start_req: dxfer_len=%d\n",
1742                                      dxfer_len));
1743
1744        if (hp->cmd_len > BLK_MAX_CDB) {
1745                long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1746                if (!long_cmdp)
1747                        return -ENOMEM;
1748        }
1749
1750        /*
1751         * NOTE
1752         *
1753         * With scsi-mq enabled, there are a fixed number of preallocated
1754         * requests equal in number to shost->can_queue.  If all of the
1755         * preallocated requests are already in use, then blk_get_request()
1756         * will sleep until an active command completes, freeing up a request.
1757         * Although waiting in an asynchronous interface is less than ideal, we
1758         * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1759         * not expect an EWOULDBLOCK from this condition.
1760         */
1761        rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1762                        REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1763        if (IS_ERR(rq)) {
1764                kfree(long_cmdp);
1765                return PTR_ERR(rq);
1766        }
1767        req = scsi_req(rq);
1768
1769        if (hp->cmd_len > BLK_MAX_CDB)
1770                req->cmd = long_cmdp;
1771        memcpy(req->cmd, cmd, hp->cmd_len);
1772        req->cmd_len = hp->cmd_len;
1773
1774        srp->rq = rq;
1775        rq->end_io_data = srp;
1776        req->retries = SG_DEFAULT_RETRIES;
1777
1778        if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1779                return 0;
1780
1781        if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1782            dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1783            blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1784                md = NULL;
1785        else
1786                md = &map_data;
1787
1788        if (md) {
1789                mutex_lock(&sfp->f_mutex);
1790                if (dxfer_len <= rsv_schp->bufflen &&
1791                    !sfp->res_in_use) {
1792                        sfp->res_in_use = 1;
1793                        sg_link_reserve(sfp, srp, dxfer_len);
1794                } else if (hp->flags & SG_FLAG_MMAP_IO) {
1795                        res = -EBUSY; /* sfp->res_in_use == 1 */
1796                        if (dxfer_len > rsv_schp->bufflen)
1797                                res = -ENOMEM;
1798                        mutex_unlock(&sfp->f_mutex);
1799                        return res;
1800                } else {
1801                        res = sg_build_indirect(req_schp, sfp, dxfer_len);
1802                        if (res) {
1803                                mutex_unlock(&sfp->f_mutex);
1804                                return res;
1805                        }
1806                }
1807                mutex_unlock(&sfp->f_mutex);
1808
1809                md->pages = req_schp->pages;
1810                md->page_order = req_schp->page_order;
1811                md->nr_entries = req_schp->k_use_sg;
1812                md->offset = 0;
1813                md->null_mapped = hp->dxferp ? 0 : 1;
1814                if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1815                        md->from_user = 1;
1816                else
1817                        md->from_user = 0;
1818        }
1819
1820        if (iov_count) {
1821                struct iovec *iov = NULL;
1822                struct iov_iter i;
1823
1824                res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1825                if (res < 0)
1826                        return res;
1827
1828                iov_iter_truncate(&i, hp->dxfer_len);
1829                if (!iov_iter_count(&i)) {
1830                        kfree(iov);
1831                        return -EINVAL;
1832                }
1833
1834                res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1835                kfree(iov);
1836        } else
1837                res = blk_rq_map_user(q, rq, md, hp->dxferp,
1838                                      hp->dxfer_len, GFP_ATOMIC);
1839
1840        if (!res) {
1841                srp->bio = rq->bio;
1842
1843                if (!md) {
1844                        req_schp->dio_in_use = 1;
1845                        hp->info |= SG_INFO_DIRECT_IO;
1846                }
1847        }
1848        return res;
1849}
1850
1851static int
1852sg_finish_rem_req(Sg_request *srp)
1853{
1854        int ret = 0;
1855
1856        Sg_fd *sfp = srp->parentfp;
1857        Sg_scatter_hold *req_schp = &srp->data;
1858
1859        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1860                                      "sg_finish_rem_req: res_used=%d\n",
1861                                      (int) srp->res_used));
1862        if (srp->bio)
1863                ret = blk_rq_unmap_user(srp->bio);
1864
1865        if (srp->rq) {
1866                scsi_req_free_cmd(scsi_req(srp->rq));
1867                blk_put_request(srp->rq);
1868        }
1869
1870        if (srp->res_used)
1871                sg_unlink_reserve(sfp, srp);
1872        else
1873                sg_remove_scat(sfp, req_schp);
1874
1875        return ret;
1876}
1877
1878static int
1879sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1880{
1881        int sg_bufflen = tablesize * sizeof(struct page *);
1882        gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1883
1884        schp->pages = kzalloc(sg_bufflen, gfp_flags);
1885        if (!schp->pages)
1886                return -ENOMEM;
1887        schp->sglist_len = sg_bufflen;
1888        return tablesize;       /* number of scat_gath elements allocated */
1889}
1890
1891static int
1892sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1893{
1894        int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1895        int sg_tablesize = sfp->parentdp->sg_tablesize;
1896        int blk_size = buff_size, order;
1897        gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1898
1899        if (blk_size < 0)
1900                return -EFAULT;
1901        if (0 == blk_size)
1902                ++blk_size;     /* don't know why */
1903        /* round request up to next highest SG_SECTOR_SZ byte boundary */
1904        blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1905        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1906                "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1907                buff_size, blk_size));
1908
1909        /* N.B. ret_sz carried into this block ... */
1910        mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1911        if (mx_sc_elems < 0)
1912                return mx_sc_elems;     /* most likely -ENOMEM */
1913
1914        num = scatter_elem_sz;
1915        if (unlikely(num != scatter_elem_sz_prev)) {
1916                if (num < PAGE_SIZE) {
1917                        scatter_elem_sz = PAGE_SIZE;
1918                        scatter_elem_sz_prev = PAGE_SIZE;
1919                } else
1920                        scatter_elem_sz_prev = num;
1921        }
1922
1923        order = get_order(num);
1924retry:
1925        ret_sz = 1 << (PAGE_SHIFT + order);
1926
1927        for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1928             k++, rem_sz -= ret_sz) {
1929
1930                num = (rem_sz > scatter_elem_sz_prev) ?
1931                        scatter_elem_sz_prev : rem_sz;
1932
1933                schp->pages[k] = alloc_pages(gfp_mask, order);
1934                if (!schp->pages[k])
1935                        goto out;
1936
1937                if (num == scatter_elem_sz_prev) {
1938                        if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1939                                scatter_elem_sz = ret_sz;
1940                                scatter_elem_sz_prev = ret_sz;
1941                        }
1942                }
1943
1944                SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1945                                 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1946                                 k, num, ret_sz));
1947        }               /* end of for loop */
1948
1949        schp->page_order = order;
1950        schp->k_use_sg = k;
1951        SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1952                         "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1953                         k, rem_sz));
1954
1955        schp->bufflen = blk_size;
1956        if (rem_sz > 0) /* must have failed */
1957                return -ENOMEM;
1958        return 0;
1959out:
1960        for (i = 0; i < k; i++)
1961                __free_pages(schp->pages[i], order);
1962
1963        if (--order >= 0)
1964                goto retry;
1965
1966        return -ENOMEM;
1967}
1968
1969static void
1970sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1971{
1972        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1973                         "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1974        if (schp->pages && schp->sglist_len > 0) {
1975                if (!schp->dio_in_use) {
1976                        int k;
1977
1978                        for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1979                                SCSI_LOG_TIMEOUT(5,
1980                                        sg_printk(KERN_INFO, sfp->parentdp,
1981                                        "sg_remove_scat: k=%d, pg=0x%p\n",
1982                                        k, schp->pages[k]));
1983                                __free_pages(schp->pages[k], schp->page_order);
1984                        }
1985
1986                        kfree(schp->pages);
1987                }
1988        }
1989        memset(schp, 0, sizeof (*schp));
1990}
1991
1992static int
1993sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1994{
1995        Sg_scatter_hold *schp = &srp->data;
1996        int k, num;
1997
1998        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1999                         "sg_read_oxfer: num_read_xfer=%d\n",
2000                         num_read_xfer));
2001        if ((!outp) || (num_read_xfer <= 0))
2002                return 0;
2003
2004        num = 1 << (PAGE_SHIFT + schp->page_order);
2005        for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2006                if (num > num_read_xfer) {
2007                        if (copy_to_user(outp, page_address(schp->pages[k]),
2008                                           num_read_xfer))
2009                                return -EFAULT;
2010                        break;
2011                } else {
2012                        if (copy_to_user(outp, page_address(schp->pages[k]),
2013                                           num))
2014                                return -EFAULT;
2015                        num_read_xfer -= num;
2016                        if (num_read_xfer <= 0)
2017                                break;
2018                        outp += num;
2019                }
2020        }
2021
2022        return 0;
2023}
2024
2025static void
2026sg_build_reserve(Sg_fd * sfp, int req_size)
2027{
2028        Sg_scatter_hold *schp = &sfp->reserve;
2029
2030        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2031                         "sg_build_reserve: req_size=%d\n", req_size));
2032        do {
2033                if (req_size < PAGE_SIZE)
2034                        req_size = PAGE_SIZE;
2035                if (0 == sg_build_indirect(schp, sfp, req_size))
2036                        return;
2037                else
2038                        sg_remove_scat(sfp, schp);
2039                req_size >>= 1; /* divide by 2 */
2040        } while (req_size > (PAGE_SIZE / 2));
2041}
2042
2043static void
2044sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2045{
2046        Sg_scatter_hold *req_schp = &srp->data;
2047        Sg_scatter_hold *rsv_schp = &sfp->reserve;
2048        int k, num, rem;
2049
2050        srp->res_used = 1;
2051        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2052                         "sg_link_reserve: size=%d\n", size));
2053        rem = size;
2054
2055        num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2056        for (k = 0; k < rsv_schp->k_use_sg; k++) {
2057                if (rem <= num) {
2058                        req_schp->k_use_sg = k + 1;
2059                        req_schp->sglist_len = rsv_schp->sglist_len;
2060                        req_schp->pages = rsv_schp->pages;
2061
2062                        req_schp->bufflen = size;
2063                        req_schp->page_order = rsv_schp->page_order;
2064                        break;
2065                } else
2066                        rem -= num;
2067        }
2068
2069        if (k >= rsv_schp->k_use_sg)
2070                SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2071                                 "sg_link_reserve: BAD size\n"));
2072}
2073
2074static void
2075sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2076{
2077        Sg_scatter_hold *req_schp = &srp->data;
2078
2079        SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2080                                      "sg_unlink_reserve: req->k_use_sg=%d\n",
2081                                      (int) req_schp->k_use_sg));
2082        req_schp->k_use_sg = 0;
2083        req_schp->bufflen = 0;
2084        req_schp->pages = NULL;
2085        req_schp->page_order = 0;
2086        req_schp->sglist_len = 0;
2087        srp->res_used = 0;
2088        /* Called without mutex lock to avoid deadlock */
2089        sfp->res_in_use = 0;
2090}
2091
2092static Sg_request *
2093sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2094{
2095        Sg_request *resp;
2096        unsigned long iflags;
2097
2098        write_lock_irqsave(&sfp->rq_list_lock, iflags);
2099        list_for_each_entry(resp, &sfp->rq_list, entry) {
2100                /* look for requests that are ready + not SG_IO owned */
2101                if ((1 == resp->done) && (!resp->sg_io_owned) &&
2102                    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2103                        resp->done = 2; /* guard against other readers */
2104                        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2105                        return resp;
2106                }
2107        }
2108        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2109        return NULL;
2110}
2111
2112/* always adds to end of list */
2113static Sg_request *
2114sg_add_request(Sg_fd * sfp)
2115{
2116        int k;
2117        unsigned long iflags;
2118        Sg_request *rp = sfp->req_arr;
2119
2120        write_lock_irqsave(&sfp->rq_list_lock, iflags);
2121        if (!list_empty(&sfp->rq_list)) {
2122                if (!sfp->cmd_q)
2123                        goto out_unlock;
2124
2125                for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2126                        if (!rp->parentfp)
2127                                break;
2128                }
2129                if (k >= SG_MAX_QUEUE)
2130                        goto out_unlock;
2131        }
2132        memset(rp, 0, sizeof (Sg_request));
2133        rp->parentfp = sfp;
2134        rp->header.duration = jiffies_to_msecs(jiffies);
2135        list_add_tail(&rp->entry, &sfp->rq_list);
2136        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2137        return rp;
2138out_unlock:
2139        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2140        return NULL;
2141}
2142
2143/* Return of 1 for found; 0 for not found */
2144static int
2145sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2146{
2147        unsigned long iflags;
2148        int res = 0;
2149
2150        if (!sfp || !srp || list_empty(&sfp->rq_list))
2151                return res;
2152        write_lock_irqsave(&sfp->rq_list_lock, iflags);
2153        if (!list_empty(&srp->entry)) {
2154                list_del(&srp->entry);
2155                srp->parentfp = NULL;
2156                res = 1;
2157        }
2158        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2159        return res;
2160}
2161
2162static Sg_fd *
2163sg_add_sfp(Sg_device * sdp)
2164{
2165        Sg_fd *sfp;
2166        unsigned long iflags;
2167        int bufflen;
2168
2169        sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2170        if (!sfp)
2171                return ERR_PTR(-ENOMEM);
2172
2173        init_waitqueue_head(&sfp->read_wait);
2174        rwlock_init(&sfp->rq_list_lock);
2175        INIT_LIST_HEAD(&sfp->rq_list);
2176        kref_init(&sfp->f_ref);
2177        mutex_init(&sfp->f_mutex);
2178        sfp->timeout = SG_DEFAULT_TIMEOUT;
2179        sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2180        sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2181        sfp->cmd_q = SG_DEF_COMMAND_Q;
2182        sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2183        sfp->parentdp = sdp;
2184        write_lock_irqsave(&sdp->sfd_lock, iflags);
2185        if (atomic_read(&sdp->detaching)) {
2186                write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187                kfree(sfp);
2188                return ERR_PTR(-ENODEV);
2189        }
2190        list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2191        write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2192        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2193                                      "sg_add_sfp: sfp=0x%p\n", sfp));
2194        if (unlikely(sg_big_buff != def_reserved_size))
2195                sg_big_buff = def_reserved_size;
2196
2197        bufflen = min_t(int, sg_big_buff,
2198                        max_sectors_bytes(sdp->device->request_queue));
2199        sg_build_reserve(sfp, bufflen);
2200        SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2201                                      "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2202                                      sfp->reserve.bufflen,
2203                                      sfp->reserve.k_use_sg));
2204
2205        kref_get(&sdp->d_ref);
2206        __module_get(THIS_MODULE);
2207        return sfp;
2208}
2209
2210static void
2211sg_remove_sfp_usercontext(struct work_struct *work)
2212{
2213        struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2214        struct sg_device *sdp = sfp->parentdp;
2215        Sg_request *srp;
2216        unsigned long iflags;
2217
2218        /* Cleanup any responses which were never read(). */
2219        write_lock_irqsave(&sfp->rq_list_lock, iflags);
2220        while (!list_empty(&sfp->rq_list)) {
2221                srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2222                sg_finish_rem_req(srp);
2223                list_del(&srp->entry);
2224                srp->parentfp = NULL;
2225        }
2226        write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2227
2228        if (sfp->reserve.bufflen > 0) {
2229                SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2230                                "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2231                                (int) sfp->reserve.bufflen,
2232                                (int) sfp->reserve.k_use_sg));
2233                sg_remove_scat(sfp, &sfp->reserve);
2234        }
2235
2236        SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2237                        "sg_remove_sfp: sfp=0x%p\n", sfp));
2238        kfree(sfp);
2239
2240        scsi_device_put(sdp->device);
2241        kref_put(&sdp->d_ref, sg_device_destroy);
2242        module_put(THIS_MODULE);
2243}
2244
2245static void
2246sg_remove_sfp(struct kref *kref)
2247{
2248        struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2249        struct sg_device *sdp = sfp->parentdp;
2250        unsigned long iflags;
2251
2252        write_lock_irqsave(&sdp->sfd_lock, iflags);
2253        list_del(&sfp->sfd_siblings);
2254        write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2255
2256        INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2257        schedule_work(&sfp->ew.work);
2258}
2259
2260#ifdef CONFIG_SCSI_PROC_FS
2261static int
2262sg_idr_max_id(int id, void *p, void *data)
2263{
2264        int *k = data;
2265
2266        if (*k < id)
2267                *k = id;
2268
2269        return 0;
2270}
2271
2272static int
2273sg_last_dev(void)
2274{
2275        int k = -1;
2276        unsigned long iflags;
2277
2278        read_lock_irqsave(&sg_index_lock, iflags);
2279        idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2280        read_unlock_irqrestore(&sg_index_lock, iflags);
2281        return k + 1;           /* origin 1 */
2282}
2283#endif
2284
2285/* must be called with sg_index_lock held */
2286static Sg_device *sg_lookup_dev(int dev)
2287{
2288        return idr_find(&sg_index_idr, dev);
2289}
2290
2291static Sg_device *
2292sg_get_dev(int dev)
2293{
2294        struct sg_device *sdp;
2295        unsigned long flags;
2296
2297        read_lock_irqsave(&sg_index_lock, flags);
2298        sdp = sg_lookup_dev(dev);
2299        if (!sdp)
2300                sdp = ERR_PTR(-ENXIO);
2301        else if (atomic_read(&sdp->detaching)) {
2302                /* If sdp->detaching, then the refcount may already be 0, in
2303                 * which case it would be a bug to do kref_get().
2304                 */
2305                sdp = ERR_PTR(-ENODEV);
2306        } else
2307                kref_get(&sdp->d_ref);
2308        read_unlock_irqrestore(&sg_index_lock, flags);
2309
2310        return sdp;
2311}
2312
2313#ifdef CONFIG_SCSI_PROC_FS
2314static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2315
2316static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2317static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2318                                  size_t count, loff_t *off);
2319static const struct proc_ops adio_proc_ops = {
2320        .proc_open      = sg_proc_single_open_adio,
2321        .proc_read      = seq_read,
2322        .proc_lseek     = seq_lseek,
2323        .proc_write     = sg_proc_write_adio,
2324        .proc_release   = single_release,
2325};
2326
2327static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2328static ssize_t sg_proc_write_dressz(struct file *filp, 
2329                const char __user *buffer, size_t count, loff_t *off);
2330static const struct proc_ops dressz_proc_ops = {
2331        .proc_open      = sg_proc_single_open_dressz,
2332        .proc_read      = seq_read,
2333        .proc_lseek     = seq_lseek,
2334        .proc_write     = sg_proc_write_dressz,
2335        .proc_release   = single_release,
2336};
2337
2338static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2339static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2340static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2341static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2342static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2343static void dev_seq_stop(struct seq_file *s, void *v);
2344static const struct seq_operations dev_seq_ops = {
2345        .start = dev_seq_start,
2346        .next  = dev_seq_next,
2347        .stop  = dev_seq_stop,
2348        .show  = sg_proc_seq_show_dev,
2349};
2350
2351static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2352static const struct seq_operations devstrs_seq_ops = {
2353        .start = dev_seq_start,
2354        .next  = dev_seq_next,
2355        .stop  = dev_seq_stop,
2356        .show  = sg_proc_seq_show_devstrs,
2357};
2358
2359static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2360static const struct seq_operations debug_seq_ops = {
2361        .start = dev_seq_start,
2362        .next  = dev_seq_next,
2363        .stop  = dev_seq_stop,
2364        .show  = sg_proc_seq_show_debug,
2365};
2366
2367static int
2368sg_proc_init(void)
2369{
2370        struct proc_dir_entry *p;
2371
2372        p = proc_mkdir("scsi/sg", NULL);
2373        if (!p)
2374                return 1;
2375
2376        proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2377        proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2378        proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2379        proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2380        proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2381        proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2382        proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2383        return 0;
2384}
2385
2386
2387static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2388{
2389        seq_printf(s, "%d\n", *((int *)s->private));
2390        return 0;
2391}
2392
2393static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2394{
2395        return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2396}
2397
2398static ssize_t 
2399sg_proc_write_adio(struct file *filp, const char __user *buffer,
2400                   size_t count, loff_t *off)
2401{
2402        int err;
2403        unsigned long num;
2404
2405        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2406                return -EACCES;
2407        err = kstrtoul_from_user(buffer, count, 0, &num);
2408        if (err)
2409                return err;
2410        sg_allow_dio = num ? 1 : 0;
2411        return count;
2412}
2413
2414static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2415{
2416        return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2417}
2418
2419static ssize_t 
2420sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2421                     size_t count, loff_t *off)
2422{
2423        int err;
2424        unsigned long k = ULONG_MAX;
2425
2426        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2427                return -EACCES;
2428
2429        err = kstrtoul_from_user(buffer, count, 0, &k);
2430        if (err)
2431                return err;
2432        if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2433                sg_big_buff = k;
2434                return count;
2435        }
2436        return -ERANGE;
2437}
2438
2439static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2440{
2441        seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2442                   sg_version_date);
2443        return 0;
2444}
2445
2446static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2447{
2448        seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2449        return 0;
2450}
2451
2452struct sg_proc_deviter {
2453        loff_t  index;
2454        size_t  max;
2455};
2456
2457static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2458{
2459        struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2460
2461        s->private = it;
2462        if (! it)
2463                return NULL;
2464
2465        it->index = *pos;
2466        it->max = sg_last_dev();
2467        if (it->index >= it->max)
2468                return NULL;
2469        return it;
2470}
2471
2472static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2473{
2474        struct sg_proc_deviter * it = s->private;
2475
2476        *pos = ++it->index;
2477        return (it->index < it->max) ? it : NULL;
2478}
2479
2480static void dev_seq_stop(struct seq_file *s, void *v)
2481{
2482        kfree(s->private);
2483}
2484
2485static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2486{
2487        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2488        Sg_device *sdp;
2489        struct scsi_device *scsidp;
2490        unsigned long iflags;
2491
2492        read_lock_irqsave(&sg_index_lock, iflags);
2493        sdp = it ? sg_lookup_dev(it->index) : NULL;
2494        if ((NULL == sdp) || (NULL == sdp->device) ||
2495            (atomic_read(&sdp->detaching)))
2496                seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2497        else {
2498                scsidp = sdp->device;
2499                seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2500                              scsidp->host->host_no, scsidp->channel,
2501                              scsidp->id, scsidp->lun, (int) scsidp->type,
2502                              1,
2503                              (int) scsidp->queue_depth,
2504                              (int) scsi_device_busy(scsidp),
2505                              (int) scsi_device_online(scsidp));
2506        }
2507        read_unlock_irqrestore(&sg_index_lock, iflags);
2508        return 0;
2509}
2510
2511static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2512{
2513        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2514        Sg_device *sdp;
2515        struct scsi_device *scsidp;
2516        unsigned long iflags;
2517
2518        read_lock_irqsave(&sg_index_lock, iflags);
2519        sdp = it ? sg_lookup_dev(it->index) : NULL;
2520        scsidp = sdp ? sdp->device : NULL;
2521        if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2522                seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2523                           scsidp->vendor, scsidp->model, scsidp->rev);
2524        else
2525                seq_puts(s, "<no active device>\n");
2526        read_unlock_irqrestore(&sg_index_lock, iflags);
2527        return 0;
2528}
2529
2530/* must be called while holding sg_index_lock */
2531static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2532{
2533        int k, new_interface, blen, usg;
2534        Sg_request *srp;
2535        Sg_fd *fp;
2536        const sg_io_hdr_t *hp;
2537        const char * cp;
2538        unsigned int ms;
2539
2540        k = 0;
2541        list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2542                k++;
2543                read_lock(&fp->rq_list_lock); /* irqs already disabled */
2544                seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2545                           "(res)sgat=%d low_dma=%d\n", k,
2546                           jiffies_to_msecs(fp->timeout),
2547                           fp->reserve.bufflen,
2548                           (int) fp->reserve.k_use_sg, 0);
2549                seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2550                           (int) fp->cmd_q, (int) fp->force_packid,
2551                           (int) fp->keep_orphan);
2552                list_for_each_entry(srp, &fp->rq_list, entry) {
2553                        hp = &srp->header;
2554                        new_interface = (hp->interface_id == '\0') ? 0 : 1;
2555                        if (srp->res_used) {
2556                                if (new_interface &&
2557                                    (SG_FLAG_MMAP_IO & hp->flags))
2558                                        cp = "     mmap>> ";
2559                                else
2560                                        cp = "     rb>> ";
2561                        } else {
2562                                if (SG_INFO_DIRECT_IO_MASK & hp->info)
2563                                        cp = "     dio>> ";
2564                                else
2565                                        cp = "     ";
2566                        }
2567                        seq_puts(s, cp);
2568                        blen = srp->data.bufflen;
2569                        usg = srp->data.k_use_sg;
2570                        seq_puts(s, srp->done ?
2571                                 ((1 == srp->done) ?  "rcv:" : "fin:")
2572                                  : "act:");
2573                        seq_printf(s, " id=%d blen=%d",
2574                                   srp->header.pack_id, blen);
2575                        if (srp->done)
2576                                seq_printf(s, " dur=%d", hp->duration);
2577                        else {
2578                                ms = jiffies_to_msecs(jiffies);
2579                                seq_printf(s, " t_o/elap=%d/%d",
2580                                        (new_interface ? hp->timeout :
2581                                                  jiffies_to_msecs(fp->timeout)),
2582                                        (ms > hp->duration ? ms - hp->duration : 0));
2583                        }
2584                        seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2585                                   (int) srp->data.cmd_opcode);
2586                }
2587                if (list_empty(&fp->rq_list))
2588                        seq_puts(s, "     No requests active\n");
2589                read_unlock(&fp->rq_list_lock);
2590        }
2591}
2592
2593static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2594{
2595        struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2596        Sg_device *sdp;
2597        unsigned long iflags;
2598
2599        if (it && (0 == it->index))
2600                seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2601                           (int)it->max, sg_big_buff);
2602
2603        read_lock_irqsave(&sg_index_lock, iflags);
2604        sdp = it ? sg_lookup_dev(it->index) : NULL;
2605        if (NULL == sdp)
2606                goto skip;
2607        read_lock(&sdp->sfd_lock);
2608        if (!list_empty(&sdp->sfds)) {
2609                seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2610                if (atomic_read(&sdp->detaching))
2611                        seq_puts(s, "detaching pending close ");
2612                else if (sdp->device) {
2613                        struct scsi_device *scsidp = sdp->device;
2614
2615                        seq_printf(s, "%d:%d:%d:%llu   em=%d",
2616                                   scsidp->host->host_no,
2617                                   scsidp->channel, scsidp->id,
2618                                   scsidp->lun,
2619                                   scsidp->host->hostt->emulated);
2620                }
2621                seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2622                           sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2623                sg_proc_debug_helper(s, sdp);
2624        }
2625        read_unlock(&sdp->sfd_lock);
2626skip:
2627        read_unlock_irqrestore(&sg_index_lock, iflags);
2628        return 0;
2629}
2630
2631#endif                          /* CONFIG_SCSI_PROC_FS */
2632
2633module_init(init_sg);
2634module_exit(exit_sg);
2635
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.