drivers/scsi/sg.c

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