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