drivers/scsi/sg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  History:
   4  *  Started: Aug 9 by Lawrence Foard ([email protected]),
   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 ([email protected]), 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/major.h>
  35 #include <linux/slab.h>
  36 #include <linux/fcntl.h>
  37 #include <linux/init.h>
  38 #include <linux/poll.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/cdev.h>
  41 #include <linux/idr.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/delay.h>
  45 #include <linux/blktrace_api.h>
  46 #include <linux/mutex.h>
  47 #include <linux/atomic.h>
  48 #include <linux/ratelimit.h>
  49 #include <linux/uio.h>
  50 #include <linux/cred.h> /* for sg_check_file_access() */
  51
  52 #include "scsi.h"
  53 #include <scsi/scsi_dbg.h>
  54 #include <scsi/scsi_host.h>
  55 #include <scsi/scsi_driver.h>
  56 #include <scsi/scsi_ioctl.h>
  57 #include <scsi/sg.h>
  58
  59 #include "scsi_logging.h"
  60
  61 #ifdef CONFIG_SCSI_PROC_FS
  62 #include <linux/proc_fs.h>
  63 static char *sg_version_date = "20140603";
  64
  65 static int sg_proc_init(void);
  66 #endif
  67
  68 #define SG_ALLOW_DIO_DEF 0
  69
  70 #define SG_MAX_DEVS 32768
  71
  72 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  73  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  74  * than 16 bytes are "variable length" whose length is a multiple of 4
  75  */
  76 #define SG_MAX_CDB_SIZE 252
  77
  78 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  79
  80 static int sg_big_buff = SG_DEF_RESERVED_SIZE;
  81 /* N.B. This variable is readable and writeable via
  82    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  83    of this size (or less if there is not enough memory) will be reserved
  84    for use by this file descriptor. [Deprecated usage: this variable is also
  85    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  86    the kernel (i.e. it is not a module).] */
  87 static int def_reserved_size = -1;      /* picks up init parameter */
  88 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  89
  90 static int scatter_elem_sz = SG_SCATTER_SZ;
  91 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  92
  93 #define SG_SECTOR_SZ 512
  94
  95 static int sg_add_device(struct device *, struct class_interface *);
  96 static void sg_remove_device(struct device *, struct class_interface *);
  97
  98 static DEFINE_IDR(sg_index_idr);
  99 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 100                                                            file descriptor list for device */
 101
 102 static struct class_interface sg_interface = {
 103         .add_dev        = sg_add_device,
 104         .remove_dev     = sg_remove_device,
 105 };
 106
 107 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 108         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 109         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 110         unsigned bufflen;       /* Size of (aggregate) data buffer */
 111         struct page **pages;
 112         int page_order;
 113         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 114         unsigned char cmd_opcode; /* first byte of command */
 115 } Sg_scatter_hold;
 116
 117 struct sg_device;               /* forward declarations */
 118 struct sg_fd;
 119
 120 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 121         struct list_head entry; /* list entry */
 122         struct sg_fd *parentfp; /* NULL -> not in use */
 123         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 124         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 125         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 126         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 127         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 128         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 129         /* done protected by rq_list_lock */
 130         char done;              /* 0->before bh, 1->before read, 2->read */
 131         struct request *rq;
 132         struct bio *bio;
 133         struct execute_work ew;
 134 } Sg_request;
 135
 136 typedef struct sg_fd {          /* holds the state of a file descriptor */
 137         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 138         struct sg_device *parentdp;     /* owning device */
 139         wait_queue_head_t read_wait;    /* queue read until command done */
 140         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 141         struct mutex f_mutex;   /* protect against changes in this fd */
 142         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 143         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 144         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 145         struct list_head rq_list; /* head of request list */
 146         struct fasync_struct *async_qp; /* used by asynchronous notification */
 147         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 148         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 149         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 150         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 151         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 152         char mmap_called;       /* 0 -> mmap() never called on this fd */
 153         char res_in_use;        /* 1 -> 'reserve' array in use */
 154         struct kref f_ref;
 155         struct execute_work ew;
 156 } Sg_fd;
 157
 158 typedef struct sg_device { /* holds the state of each scsi generic device */
 159         struct scsi_device *device;
 160         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 161         struct mutex open_rel_lock;     /* held when in open() or release() */
 162         int sg_tablesize;       /* adapter's max scatter-gather table size */
 163         u32 index;              /* device index number */
 164         struct list_head sfds;
 165         rwlock_t sfd_lock;      /* protect access to sfd list */
 166         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 167         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 168         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 169         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 170         char name[DISK_NAME_LEN];
 171         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 172         struct kref d_ref;
 173 } Sg_device;
 174
 175 /* tasklet or soft irq callback */
 176 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 177 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 178 static int sg_finish_rem_req(Sg_request * srp);
 179 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 180 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 181                            Sg_request * srp);
 182 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 183                         const char __user *buf, size_t count, int blocking,
 184                         int read_only, int sg_io_owned, Sg_request **o_srp);
 185 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 186                            unsigned char *cmnd, int timeout, int blocking);
 187 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 188 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 189 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 190 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 191 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 192 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 193 static void sg_remove_sfp(struct kref *);
 194 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 195 static Sg_request *sg_add_request(Sg_fd * sfp);
 196 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 197 static Sg_device *sg_get_dev(int dev);
 198 static void sg_device_destroy(struct kref *kref);
 199
 200 #define SZ_SG_HEADER sizeof(struct sg_header)
 201 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 202 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 203 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 204
 205 #define sg_printk(prefix, sdp, fmt, a...) \
 206         sdev_prefix_printk(prefix, (sdp)->device, (sdp)->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         if (!scsi_cmd_allowed(cmd, filp->f_mode))
 242                 return -EPERM;
 243         return 0;
 244 }
 245
 246 static int
 247 open_wait(Sg_device *sdp, int flags)
 248 {
 249         int retval = 0;
 250
 251         if (flags & O_EXCL) {
 252                 while (sdp->open_cnt > 0) {
 253                         mutex_unlock(&sdp->open_rel_lock);
 254                         retval = wait_event_interruptible(sdp->open_wait,
 255                                         (atomic_read(&sdp->detaching) ||
 256                                          !sdp->open_cnt));
 257                         mutex_lock(&sdp->open_rel_lock);
 258
 259                         if (retval) /* -ERESTARTSYS */
 260                                 return retval;
 261                         if (atomic_read(&sdp->detaching))
 262                                 return -ENODEV;
 263                 }
 264         } else {
 265                 while (sdp->exclude) {
 266                         mutex_unlock(&sdp->open_rel_lock);
 267                         retval = wait_event_interruptible(sdp->open_wait,
 268                                         (atomic_read(&sdp->detaching) ||
 269                                          !sdp->exclude));
 270                         mutex_lock(&sdp->open_rel_lock);
 271
 272                         if (retval) /* -ERESTARTSYS */
 273                                 return retval;
 274                         if (atomic_read(&sdp->detaching))
 275                                 return -ENODEV;
 276                 }
 277         }
 278
 279         return retval;
 280 }
 281
 282 /* Returns 0 on success, else a negated errno value */
 283 static int
 284 sg_open(struct inode *inode, struct file *filp)
 285 {
 286         int dev = iminor(inode);
 287         int flags = filp->f_flags;
 288         struct request_queue *q;
 289         Sg_device *sdp;
 290         Sg_fd *sfp;
 291         int retval;
 292
 293         nonseekable_open(inode, filp);
 294         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 295                 return -EPERM; /* Can't lock it with read only access */
 296         sdp = sg_get_dev(dev);
 297         if (IS_ERR(sdp))
 298                 return PTR_ERR(sdp);
 299
 300         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 301                                       "sg_open: flags=0x%x\n", flags));
 302
 303         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 304         /* Prevent the device driver from vanishing while we sleep */
 305         retval = scsi_device_get(sdp->device);
 306         if (retval)
 307                 goto sg_put;
 308
 309         retval = scsi_autopm_get_device(sdp->device);
 310         if (retval)
 311                 goto sdp_put;
 312
 313         /* scsi_block_when_processing_errors() may block so bypass
 314          * check if O_NONBLOCK. Permits SCSI commands to be issued
 315          * during error recovery. Tread carefully. */
 316         if (!((flags & O_NONBLOCK) ||
 317               scsi_block_when_processing_errors(sdp->device))) {
 318                 retval = -ENXIO;
 319                 /* we are in error recovery for this device */
 320                 goto error_out;
 321         }
 322
 323         mutex_lock(&sdp->open_rel_lock);
 324         if (flags & O_NONBLOCK) {
 325                 if (flags & O_EXCL) {
 326                         if (sdp->open_cnt > 0) {
 327                                 retval = -EBUSY;
 328                                 goto error_mutex_locked;
 329                         }
 330                 } else {
 331                         if (sdp->exclude) {
 332                                 retval = -EBUSY;
 333                                 goto error_mutex_locked;
 334                         }
 335                 }
 336         } else {
 337                 retval = open_wait(sdp, flags);
 338                 if (retval) /* -ERESTARTSYS or -ENODEV */
 339                         goto error_mutex_locked;
 340         }
 341
 342         /* N.B. at this point we are holding the open_rel_lock */
 343         if (flags & O_EXCL)
 344                 sdp->exclude = true;
 345
 346         if (sdp->open_cnt < 1) {  /* no existing opens */
 347                 sdp->sgdebug = 0;
 348                 q = sdp->device->request_queue;
 349                 sdp->sg_tablesize = queue_max_segments(q);
 350         }
 351         sfp = sg_add_sfp(sdp);
 352         if (IS_ERR(sfp)) {
 353                 retval = PTR_ERR(sfp);
 354                 goto out_undo;
 355         }
 356
 357         filp->private_data = sfp;
 358         sdp->open_cnt++;
 359         mutex_unlock(&sdp->open_rel_lock);
 360
 361         retval = 0;
 362 sg_put:
 363         kref_put(&sdp->d_ref, sg_device_destroy);
 364         return retval;
 365
 366 out_undo:
 367         if (flags & O_EXCL) {
 368                 sdp->exclude = false;   /* undo if error */
 369                 wake_up_interruptible(&sdp->open_wait);
 370         }
 371 error_mutex_locked:
 372         mutex_unlock(&sdp->open_rel_lock);
 373 error_out:
 374         scsi_autopm_put_device(sdp->device);
 375 sdp_put:
 376         scsi_device_put(sdp->device);
 377         goto sg_put;
 378 }
 379
 380 /* Release resources associated with a successful sg_open()
 381  * Returns 0 on success, else a negated errno value */
 382 static int
 383 sg_release(struct inode *inode, struct file *filp)
 384 {
 385         Sg_device *sdp;
 386         Sg_fd *sfp;
 387
 388         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 389                 return -ENXIO;
 390         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 391
 392         mutex_lock(&sdp->open_rel_lock);
 393         scsi_autopm_put_device(sdp->device);
 394         kref_put(&sfp->f_ref, sg_remove_sfp);
 395         sdp->open_cnt--;
 396
 397         /* possibly many open()s waiting on exlude clearing, start many;
 398          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 399         if (sdp->exclude) {
 400                 sdp->exclude = false;
 401                 wake_up_interruptible_all(&sdp->open_wait);
 402         } else if (0 == sdp->open_cnt) {
 403                 wake_up_interruptible(&sdp->open_wait);
 404         }
 405         mutex_unlock(&sdp->open_rel_lock);
 406         return 0;
 407 }
 408
 409 static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
 410 {
 411         struct sg_header __user *old_hdr = buf;
 412         int reply_len;
 413
 414         if (count >= SZ_SG_HEADER) {
 415                 /* negative reply_len means v3 format, otherwise v1/v2 */
 416                 if (get_user(reply_len, &old_hdr->reply_len))
 417                         return -EFAULT;
 418
 419                 if (reply_len >= 0)
 420                         return get_user(*pack_id, &old_hdr->pack_id);
 421
 422                 if (in_compat_syscall() &&
 423                     count >= sizeof(struct compat_sg_io_hdr)) {
 424                         struct compat_sg_io_hdr __user *hp = buf;
 425
 426                         return get_user(*pack_id, &hp->pack_id);
 427                 }
 428
 429                 if (count >= sizeof(struct sg_io_hdr)) {
 430                         struct sg_io_hdr __user *hp = buf;
 431
 432                         return get_user(*pack_id, &hp->pack_id);
 433                 }
 434         }
 435
 436         /* no valid header was passed, so ignore the pack_id */
 437         *pack_id = -1;
 438         return 0;
 439 }
 440
 441 static ssize_t
 442 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 443 {
 444         Sg_device *sdp;
 445         Sg_fd *sfp;
 446         Sg_request *srp;
 447         int req_pack_id = -1;
 448         sg_io_hdr_t *hp;
 449         struct sg_header *old_hdr;
 450         int retval;
 451
 452         /*
 453          * This could cause a response to be stranded. Close the associated
 454          * file descriptor to free up any resources being held.
 455          */
 456         retval = sg_check_file_access(filp, __func__);
 457         if (retval)
 458                 return retval;
 459
 460         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 461                 return -ENXIO;
 462         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 463                                       "sg_read: count=%d\n", (int) count));
 464
 465         if (sfp->force_packid)
 466                 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
 467         if (retval)
 468                 return retval;
 469
 470         srp = sg_get_rq_mark(sfp, req_pack_id);
 471         if (!srp) {             /* now wait on packet to arrive */
 472                 if (atomic_read(&sdp->detaching))
 473                         return -ENODEV;
 474                 if (filp->f_flags & O_NONBLOCK)
 475                         return -EAGAIN;
 476                 retval = wait_event_interruptible(sfp->read_wait,
 477                         (atomic_read(&sdp->detaching) ||
 478                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 479                 if (atomic_read(&sdp->detaching))
 480                         return -ENODEV;
 481                 if (retval)
 482                         /* -ERESTARTSYS as signal hit process */
 483                         return retval;
 484         }
 485         if (srp->header.interface_id != '\0')
 486                 return sg_new_read(sfp, buf, count, srp);
 487
 488         hp = &srp->header;
 489         old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
 490         if (!old_hdr)
 491                 return -ENOMEM;
 492
 493         old_hdr->reply_len = (int) hp->timeout;
 494         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 495         old_hdr->pack_id = hp->pack_id;
 496         old_hdr->twelve_byte =
 497             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 498         old_hdr->target_status = hp->masked_status;
 499         old_hdr->host_status = hp->host_status;
 500         old_hdr->driver_status = hp->driver_status;
 501         if ((CHECK_CONDITION & hp->masked_status) ||
 502             (srp->sense_b[0] & 0x70) == 0x70) {
 503                 old_hdr->driver_status = DRIVER_SENSE;
 504                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 505                        sizeof (old_hdr->sense_buffer));
 506         }
 507         switch (hp->host_status) {
 508         /* This setup of 'result' is for backward compatibility and is best
 509            ignored by the user who should use target, host + driver status */
 510         case DID_OK:
 511         case DID_PASSTHROUGH:
 512         case DID_SOFT_ERROR:
 513                 old_hdr->result = 0;
 514                 break;
 515         case DID_NO_CONNECT:
 516         case DID_BUS_BUSY:
 517         case DID_TIME_OUT:
 518                 old_hdr->result = EBUSY;
 519                 break;
 520         case DID_BAD_TARGET:
 521         case DID_ABORT:
 522         case DID_PARITY:
 523         case DID_RESET:
 524         case DID_BAD_INTR:
 525                 old_hdr->result = EIO;
 526                 break;
 527         case DID_ERROR:
 528                 old_hdr->result = (srp->sense_b[0] == 0 &&
 529                                   hp->masked_status == GOOD) ? 0 : EIO;
 530                 break;
 531         default:
 532                 old_hdr->result = EIO;
 533                 break;
 534         }
 535
 536         /* Now copy the result back to the user buffer.  */
 537         if (count >= SZ_SG_HEADER) {
 538                 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 539                         retval = -EFAULT;
 540                         goto free_old_hdr;
 541                 }
 542                 buf += SZ_SG_HEADER;
 543                 if (count > old_hdr->reply_len)
 544                         count = old_hdr->reply_len;
 545                 if (count > SZ_SG_HEADER) {
 546                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 547                                 retval = -EFAULT;
 548                                 goto free_old_hdr;
 549                         }
 550                 }
 551         } else
 552                 count = (old_hdr->result == 0) ? 0 : -EIO;
 553         sg_finish_rem_req(srp);
 554         sg_remove_request(sfp, srp);
 555         retval = count;
 556 free_old_hdr:
 557         kfree(old_hdr);
 558         return retval;
 559 }
 560
 561 static ssize_t
 562 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 563 {
 564         sg_io_hdr_t *hp = &srp->header;
 565         int err = 0, err2;
 566         int len;
 567
 568         if (in_compat_syscall()) {
 569                 if (count < sizeof(struct compat_sg_io_hdr)) {
 570                         err = -EINVAL;
 571                         goto err_out;
 572                 }
 573         } else if (count < SZ_SG_IO_HDR) {
 574                 err = -EINVAL;
 575                 goto err_out;
 576         }
 577         hp->sb_len_wr = 0;
 578         if ((hp->mx_sb_len > 0) && hp->sbp) {
 579                 if ((CHECK_CONDITION & hp->masked_status) ||
 580                     (srp->sense_b[0] & 0x70) == 0x70) {
 581                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 582                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 583                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 584                         len = (len > sb_len) ? sb_len : len;
 585                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 586                                 err = -EFAULT;
 587                                 goto err_out;
 588                         }
 589                         hp->driver_status = DRIVER_SENSE;
 590                         hp->sb_len_wr = len;
 591                 }
 592         }
 593         if (hp->masked_status || hp->host_status || hp->driver_status)
 594                 hp->info |= SG_INFO_CHECK;
 595         err = put_sg_io_hdr(hp, buf);
 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 (count < SZ_SG_HEADER)
 631                 return -EIO;
 632         if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 633                 return -EFAULT;
 634         blocking = !(filp->f_flags & O_NONBLOCK);
 635         if (old_hdr.reply_len < 0)
 636                 return sg_new_write(sfp, filp, buf, count,
 637                                     blocking, 0, 0, NULL);
 638         if (count < (SZ_SG_HEADER + 6))
 639                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 640
 641         buf += SZ_SG_HEADER;
 642         if (get_user(opcode, buf))
 643                 return -EFAULT;
 644
 645         if (!(srp = sg_add_request(sfp))) {
 646                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 647                                               "sg_write: queue full\n"));
 648                 return -EDOM;
 649         }
 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                 sg_remove_request(sfp, srp);
 694                 return -EFAULT;
 695         }
 696         /*
 697          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 698          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 699          * is a non-zero input_size, so emit a warning.
 700          */
 701         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 702                 printk_ratelimited(KERN_WARNING
 703                                    "sg_write: data in/out %d/%d bytes "
 704                                    "for SCSI command 0x%x-- guessing "
 705                                    "data in;\n   program %s not setting "
 706                                    "count and/or reply_len properly\n",
 707                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 708                                    input_size, (unsigned int) cmnd[0],
 709                                    current->comm);
 710         }
 711         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 712         return (k < 0) ? k : count;
 713 }
 714
 715 static ssize_t
 716 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 717                  size_t count, int blocking, int read_only, int sg_io_owned,
 718                  Sg_request **o_srp)
 719 {
 720         int k;
 721         Sg_request *srp;
 722         sg_io_hdr_t *hp;
 723         unsigned char cmnd[SG_MAX_CDB_SIZE];
 724         int timeout;
 725         unsigned long ul_timeout;
 726
 727         if (count < SZ_SG_IO_HDR)
 728                 return -EINVAL;
 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 (get_sg_io_hdr(hp, buf)) {
 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 (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 767                 sg_remove_request(sfp, srp);
 768                 return -EFAULT;
 769         }
 770         if (read_only && sg_allow_access(file, cmnd)) {
 771                 sg_remove_request(sfp, srp);
 772                 return -EPERM;
 773         }
 774         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 775         if (k < 0)
 776                 return k;
 777         if (o_srp)
 778                 *o_srp = srp;
 779         return count;
 780 }
 781
 782 static int
 783 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 784                 unsigned char *cmnd, int timeout, int blocking)
 785 {
 786         int k, at_head;
 787         Sg_device *sdp = sfp->parentdp;
 788         sg_io_hdr_t *hp = &srp->header;
 789
 790         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 791         hp->status = 0;
 792         hp->masked_status = 0;
 793         hp->msg_status = 0;
 794         hp->info = 0;
 795         hp->host_status = 0;
 796         hp->driver_status = 0;
 797         hp->resid = 0;
 798         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 799                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 800                         (int) cmnd[0], (int) hp->cmd_len));
 801
 802         if (hp->dxfer_len >= SZ_256M) {
 803                 sg_remove_request(sfp, srp);
 804                 return -EINVAL;
 805         }
 806
 807         k = sg_start_req(srp, cmnd);
 808         if (k) {
 809                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 810                         "sg_common_write: start_req err=%d\n", k));
 811                 sg_finish_rem_req(srp);
 812                 sg_remove_request(sfp, srp);
 813                 return k;       /* probably out of space --> ENOMEM */
 814         }
 815         if (atomic_read(&sdp->detaching)) {
 816                 if (srp->bio) {
 817                         scsi_req_free_cmd(scsi_req(srp->rq));
 818                         blk_mq_free_request(srp->rq);
 819                         srp->rq = NULL;
 820                 }
 821
 822                 sg_finish_rem_req(srp);
 823                 sg_remove_request(sfp, srp);
 824                 return -ENODEV;
 825         }
 826
 827         hp->duration = jiffies_to_msecs(jiffies);
 828         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 829             (SG_FLAG_Q_AT_TAIL & hp->flags))
 830                 at_head = 0;
 831         else
 832                 at_head = 1;
 833
 834         srp->rq->timeout = timeout;
 835         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 836         blk_execute_rq_nowait(srp->rq, at_head, sg_rq_end_io);
 837         return 0;
 838 }
 839
 840 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 841 {
 842         unsigned long flags;
 843         int ret;
 844
 845         read_lock_irqsave(&sfp->rq_list_lock, flags);
 846         ret = srp->done;
 847         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 848         return ret;
 849 }
 850
 851 static int max_sectors_bytes(struct request_queue *q)
 852 {
 853         unsigned int max_sectors = queue_max_sectors(q);
 854
 855         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 856
 857         return max_sectors << 9;
 858 }
 859
 860 static void
 861 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 862 {
 863         Sg_request *srp;
 864         int val;
 865         unsigned int ms;
 866
 867         val = 0;
 868         list_for_each_entry(srp, &sfp->rq_list, entry) {
 869                 if (val >= SG_MAX_QUEUE)
 870                         break;
 871                 rinfo[val].req_state = srp->done + 1;
 872                 rinfo[val].problem =
 873                         srp->header.masked_status &
 874                         srp->header.host_status &
 875                         srp->header.driver_status;
 876                 if (srp->done)
 877                         rinfo[val].duration =
 878                                 srp->header.duration;
 879                 else {
 880                         ms = jiffies_to_msecs(jiffies);
 881                         rinfo[val].duration =
 882                                 (ms > srp->header.duration) ?
 883                                 (ms - srp->header.duration) : 0;
 884                 }
 885                 rinfo[val].orphan = srp->orphan;
 886                 rinfo[val].sg_io_owned = srp->sg_io_owned;
 887                 rinfo[val].pack_id = srp->header.pack_id;
 888                 rinfo[val].usr_ptr = srp->header.usr_ptr;
 889                 val++;
 890         }
 891 }
 892
 893 #ifdef CONFIG_COMPAT
 894 struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
 895         char req_state;
 896         char orphan;
 897         char sg_io_owned;
 898         char problem;
 899         int pack_id;
 900         compat_uptr_t usr_ptr;
 901         unsigned int duration;
 902         int unused;
 903 };
 904
 905 static int put_compat_request_table(struct compat_sg_req_info __user *o,
 906                                     struct sg_req_info *rinfo)
 907 {
 908         int i;
 909         for (i = 0; i < SG_MAX_QUEUE; i++) {
 910                 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
 911                     put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
 912                     put_user(rinfo[i].duration, &o[i].duration) ||
 913                     put_user(rinfo[i].unused, &o[i].unused))
 914                         return -EFAULT;
 915         }
 916         return 0;
 917 }
 918 #endif
 919
 920 static long
 921 sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
 922                 unsigned int cmd_in, void __user *p)
 923 {
 924         int __user *ip = p;
 925         int result, val, read_only;
 926         Sg_request *srp;
 927         unsigned long iflags;
 928
 929         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 930                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 931         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 932
 933         switch (cmd_in) {
 934         case SG_IO:
 935                 if (atomic_read(&sdp->detaching))
 936                         return -ENODEV;
 937                 if (!scsi_block_when_processing_errors(sdp->device))
 938                         return -ENXIO;
 939                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 940                                  1, read_only, 1, &srp);
 941                 if (result < 0)
 942                         return result;
 943                 result = wait_event_interruptible(sfp->read_wait,
 944                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 945                 if (atomic_read(&sdp->detaching))
 946                         return -ENODEV;
 947                 write_lock_irq(&sfp->rq_list_lock);
 948                 if (srp->done) {
 949                         srp->done = 2;
 950                         write_unlock_irq(&sfp->rq_list_lock);
 951                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 952                         return (result < 0) ? result : 0;
 953                 }
 954                 srp->orphan = 1;
 955                 write_unlock_irq(&sfp->rq_list_lock);
 956                 return result;  /* -ERESTARTSYS because signal hit process */
 957         case SG_SET_TIMEOUT:
 958                 result = get_user(val, ip);
 959                 if (result)
 960                         return result;
 961                 if (val < 0)
 962                         return -EIO;
 963                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 964                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 965                                     INT_MAX);
 966                 sfp->timeout_user = val;
 967                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 968
 969                 return 0;
 970         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 971                                 /* strange ..., for backward compatibility */
 972                 return sfp->timeout_user;
 973         case SG_SET_FORCE_LOW_DMA:
 974                 /*
 975                  * N.B. This ioctl never worked properly, but failed to
 976                  * return an error value. So returning '0' to keep compability
 977                  * with legacy applications.
 978                  */
 979                 return 0;
 980         case SG_GET_LOW_DMA:
 981                 return put_user(0, ip);
 982         case SG_GET_SCSI_ID:
 983                 {
 984                         sg_scsi_id_t v;
 985
 986                         if (atomic_read(&sdp->detaching))
 987                                 return -ENODEV;
 988                         memset(&v, 0, sizeof(v));
 989                         v.host_no = sdp->device->host->host_no;
 990                         v.channel = sdp->device->channel;
 991                         v.scsi_id = sdp->device->id;
 992                         v.lun = sdp->device->lun;
 993                         v.scsi_type = sdp->device->type;
 994                         v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
 995                         v.d_queue_depth = sdp->device->queue_depth;
 996                         if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
 997                                 return -EFAULT;
 998                         return 0;
 999                 }
1000         case SG_SET_FORCE_PACK_ID:
1001                 result = get_user(val, ip);
1002                 if (result)
1003                         return result;
1004                 sfp->force_packid = val ? 1 : 0;
1005                 return 0;
1006         case SG_GET_PACK_ID:
1007                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1008                 list_for_each_entry(srp, &sfp->rq_list, entry) {
1009                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
1010                                 read_unlock_irqrestore(&sfp->rq_list_lock,
1011                                                        iflags);
1012                                 return put_user(srp->header.pack_id, ip);
1013                         }
1014                 }
1015                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1016                 return put_user(-1, ip);
1017         case SG_GET_NUM_WAITING:
1018                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1019                 val = 0;
1020                 list_for_each_entry(srp, &sfp->rq_list, entry) {
1021                         if ((1 == srp->done) && (!srp->sg_io_owned))
1022                                 ++val;
1023                 }
1024                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1025                 return put_user(val, ip);
1026         case SG_GET_SG_TABLESIZE:
1027                 return put_user(sdp->sg_tablesize, ip);
1028         case SG_SET_RESERVED_SIZE:
1029                 result = get_user(val, ip);
1030                 if (result)
1031                         return result;
1032                 if (val < 0)
1033                         return -EINVAL;
1034                 val = min_t(int, val,
1035                             max_sectors_bytes(sdp->device->request_queue));
1036                 mutex_lock(&sfp->f_mutex);
1037                 if (val != sfp->reserve.bufflen) {
1038                         if (sfp->mmap_called ||
1039                             sfp->res_in_use) {
1040                                 mutex_unlock(&sfp->f_mutex);
1041                                 return -EBUSY;
1042                         }
1043
1044                         sg_remove_scat(sfp, &sfp->reserve);
1045                         sg_build_reserve(sfp, val);
1046                 }
1047                 mutex_unlock(&sfp->f_mutex);
1048                 return 0;
1049         case SG_GET_RESERVED_SIZE:
1050                 val = min_t(int, sfp->reserve.bufflen,
1051                             max_sectors_bytes(sdp->device->request_queue));
1052                 return put_user(val, ip);
1053         case SG_SET_COMMAND_Q:
1054                 result = get_user(val, ip);
1055                 if (result)
1056                         return result;
1057                 sfp->cmd_q = val ? 1 : 0;
1058                 return 0;
1059         case SG_GET_COMMAND_Q:
1060                 return put_user((int) sfp->cmd_q, ip);
1061         case SG_SET_KEEP_ORPHAN:
1062                 result = get_user(val, ip);
1063                 if (result)
1064                         return result;
1065                 sfp->keep_orphan = val;
1066                 return 0;
1067         case SG_GET_KEEP_ORPHAN:
1068                 return put_user((int) sfp->keep_orphan, ip);
1069         case SG_NEXT_CMD_LEN:
1070                 result = get_user(val, ip);
1071                 if (result)
1072                         return result;
1073                 if (val > SG_MAX_CDB_SIZE)
1074                         return -ENOMEM;
1075                 sfp->next_cmd_len = (val > 0) ? val : 0;
1076                 return 0;
1077         case SG_GET_VERSION_NUM:
1078                 return put_user(sg_version_num, ip);
1079         case SG_GET_ACCESS_COUNT:
1080                 /* faked - we don't have a real access count anymore */
1081                 val = (sdp->device ? 1 : 0);
1082                 return put_user(val, ip);
1083         case SG_GET_REQUEST_TABLE:
1084                 {
1085                         sg_req_info_t *rinfo;
1086
1087                         rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1088                                         GFP_KERNEL);
1089                         if (!rinfo)
1090                                 return -ENOMEM;
1091                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1092                         sg_fill_request_table(sfp, rinfo);
1093                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1094         #ifdef CONFIG_COMPAT
1095                         if (in_compat_syscall())
1096                                 result = put_compat_request_table(p, rinfo);
1097                         else
1098         #endif
1099                                 result = copy_to_user(p, rinfo,
1100                                                       SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1101                         result = result ? -EFAULT : 0;
1102                         kfree(rinfo);
1103                         return result;
1104                 }
1105         case SG_EMULATED_HOST:
1106                 if (atomic_read(&sdp->detaching))
1107                         return -ENODEV;
1108                 return put_user(sdp->device->host->hostt->emulated, ip);
1109         case SCSI_IOCTL_SEND_COMMAND:
1110                 if (atomic_read(&sdp->detaching))
1111                         return -ENODEV;
1112                 return scsi_ioctl(sdp->device, filp->f_mode, cmd_in, p);
1113         case SG_SET_DEBUG:
1114                 result = get_user(val, ip);
1115                 if (result)
1116                         return result;
1117                 sdp->sgdebug = (char) val;
1118                 return 0;
1119         case BLKSECTGET:
1120                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1121                                 ip);
1122         case BLKTRACESETUP:
1123                 return blk_trace_setup(sdp->device->request_queue, sdp->name,
1124                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1125                                        NULL, p);
1126         case BLKTRACESTART:
1127                 return blk_trace_startstop(sdp->device->request_queue, 1);
1128         case BLKTRACESTOP:
1129                 return blk_trace_startstop(sdp->device->request_queue, 0);
1130         case BLKTRACETEARDOWN:
1131                 return blk_trace_remove(sdp->device->request_queue);
1132         case SCSI_IOCTL_GET_IDLUN:
1133         case SCSI_IOCTL_GET_BUS_NUMBER:
1134         case SCSI_IOCTL_PROBE_HOST:
1135         case SG_GET_TRANSFORM:
1136         case SG_SCSI_RESET:
1137                 if (atomic_read(&sdp->detaching))
1138                         return -ENODEV;
1139                 break;
1140         default:
1141                 if (read_only)
1142                         return -EPERM;  /* don't know so take safe approach */
1143                 break;
1144         }
1145
1146         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1147                         cmd_in, filp->f_flags & O_NDELAY);
1148         if (result)
1149                 return result;
1150
1151         return -ENOIOCTLCMD;
1152 }
1153
1154 static long
1155 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1156 {
1157         void __user *p = (void __user *)arg;
1158         Sg_device *sdp;
1159         Sg_fd *sfp;
1160         int ret;
1161
1162         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1163                 return -ENXIO;
1164
1165         ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1166         if (ret != -ENOIOCTLCMD)
1167                 return ret;
1168         return scsi_ioctl(sdp->device, filp->f_mode, cmd_in, p);
1169 }
1170
1171 static __poll_t
1172 sg_poll(struct file *filp, poll_table * wait)
1173 {
1174         __poll_t res = 0;
1175         Sg_device *sdp;
1176         Sg_fd *sfp;
1177         Sg_request *srp;
1178         int count = 0;
1179         unsigned long iflags;
1180
1181         sfp = filp->private_data;
1182         if (!sfp)
1183                 return EPOLLERR;
1184         sdp = sfp->parentdp;
1185         if (!sdp)
1186                 return EPOLLERR;
1187         poll_wait(filp, &sfp->read_wait, wait);
1188         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1189         list_for_each_entry(srp, &sfp->rq_list, entry) {
1190                 /* if any read waiting, flag it */
1191                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1192                         res = EPOLLIN | EPOLLRDNORM;
1193                 ++count;
1194         }
1195         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1196
1197         if (atomic_read(&sdp->detaching))
1198                 res |= EPOLLHUP;
1199         else if (!sfp->cmd_q) {
1200                 if (0 == count)
1201                         res |= EPOLLOUT | EPOLLWRNORM;
1202         } else if (count < SG_MAX_QUEUE)
1203                 res |= EPOLLOUT | EPOLLWRNORM;
1204         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1205                                       "sg_poll: res=0x%x\n", (__force u32) res));
1206         return res;
1207 }
1208
1209 static int
1210 sg_fasync(int fd, struct file *filp, int mode)
1211 {
1212         Sg_device *sdp;
1213         Sg_fd *sfp;
1214
1215         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1216                 return -ENXIO;
1217         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1218                                       "sg_fasync: mode=%d\n", mode));
1219
1220         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1221 }
1222
1223 static vm_fault_t
1224 sg_vma_fault(struct vm_fault *vmf)
1225 {
1226         struct vm_area_struct *vma = vmf->vma;
1227         Sg_fd *sfp;
1228         unsigned long offset, len, sa;
1229         Sg_scatter_hold *rsv_schp;
1230         int k, length;
1231
1232         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1233                 return VM_FAULT_SIGBUS;
1234         rsv_schp = &sfp->reserve;
1235         offset = vmf->pgoff << PAGE_SHIFT;
1236         if (offset >= rsv_schp->bufflen)
1237                 return VM_FAULT_SIGBUS;
1238         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1239                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1240                                       offset, rsv_schp->k_use_sg));
1241         sa = vma->vm_start;
1242         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1243         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1244                 len = vma->vm_end - sa;
1245                 len = (len < length) ? len : length;
1246                 if (offset < len) {
1247                         struct page *page = nth_page(rsv_schp->pages[k],
1248                                                      offset >> PAGE_SHIFT);
1249                         get_page(page); /* increment page count */
1250                         vmf->page = page;
1251                         return 0; /* success */
1252                 }
1253                 sa += len;
1254                 offset -= len;
1255         }
1256
1257         return VM_FAULT_SIGBUS;
1258 }
1259
1260 static const struct vm_operations_struct sg_mmap_vm_ops = {
1261         .fault = sg_vma_fault,
1262 };
1263
1264 static int
1265 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1266 {
1267         Sg_fd *sfp;
1268         unsigned long req_sz, len, sa;
1269         Sg_scatter_hold *rsv_schp;
1270         int k, length;
1271         int ret = 0;
1272
1273         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1274                 return -ENXIO;
1275         req_sz = vma->vm_end - vma->vm_start;
1276         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1277                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1278                                       (void *) vma->vm_start, (int) req_sz));
1279         if (vma->vm_pgoff)
1280                 return -EINVAL; /* want no offset */
1281         rsv_schp = &sfp->reserve;
1282         mutex_lock(&sfp->f_mutex);
1283         if (req_sz > rsv_schp->bufflen) {
1284                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1285                 goto out;
1286         }
1287
1288         sa = vma->vm_start;
1289         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1290         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1291                 len = vma->vm_end - sa;
1292                 len = (len < length) ? len : length;
1293                 sa += len;
1294         }
1295
1296         sfp->mmap_called = 1;
1297         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1298         vma->vm_private_data = sfp;
1299         vma->vm_ops = &sg_mmap_vm_ops;
1300 out:
1301         mutex_unlock(&sfp->f_mutex);
1302         return ret;
1303 }
1304
1305 static void
1306 sg_rq_end_io_usercontext(struct work_struct *work)
1307 {
1308         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1309         struct sg_fd *sfp = srp->parentfp;
1310
1311         sg_finish_rem_req(srp);
1312         sg_remove_request(sfp, srp);
1313         kref_put(&sfp->f_ref, sg_remove_sfp);
1314 }
1315
1316 /*
1317  * This function is a "bottom half" handler that is called by the mid
1318  * level when a command is completed (or has failed).
1319  */
1320 static void
1321 sg_rq_end_io(struct request *rq, blk_status_t status)
1322 {
1323         struct sg_request *srp = rq->end_io_data;
1324         struct scsi_request *req = scsi_req(rq);
1325         Sg_device *sdp;
1326         Sg_fd *sfp;
1327         unsigned long iflags;
1328         unsigned int ms;
1329         char *sense;
1330         int result, resid, done = 1;
1331
1332         if (WARN_ON(srp->done != 0))
1333                 return;
1334
1335         sfp = srp->parentfp;
1336         if (WARN_ON(sfp == NULL))
1337                 return;
1338
1339         sdp = sfp->parentdp;
1340         if (unlikely(atomic_read(&sdp->detaching)))
1341                 pr_info("%s: device detaching\n", __func__);
1342
1343         sense = req->sense;
1344         result = req->result;
1345         resid = req->resid_len;
1346
1347         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1348                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1349                                       srp->header.pack_id, result));
1350         srp->header.resid = resid;
1351         ms = jiffies_to_msecs(jiffies);
1352         srp->header.duration = (ms > srp->header.duration) ?
1353                                 (ms - srp->header.duration) : 0;
1354         if (0 != result) {
1355                 struct scsi_sense_hdr sshdr;
1356
1357                 srp->header.status = 0xff & result;
1358                 srp->header.masked_status = status_byte(result);
1359                 srp->header.msg_status = COMMAND_COMPLETE;
1360                 srp->header.host_status = host_byte(result);
1361                 srp->header.driver_status = driver_byte(result);
1362                 if ((sdp->sgdebug > 0) &&
1363                     ((CHECK_CONDITION == srp->header.masked_status) ||
1364                      (COMMAND_TERMINATED == srp->header.masked_status)))
1365                         __scsi_print_sense(sdp->device, __func__, sense,
1366                                            SCSI_SENSE_BUFFERSIZE);
1367
1368                 /* Following if statement is a patch supplied by Eric Youngdale */
1369                 if (driver_byte(result) != 0
1370                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1371                     && !scsi_sense_is_deferred(&sshdr)
1372                     && sshdr.sense_key == UNIT_ATTENTION
1373                     && sdp->device->removable) {
1374                         /* Detected possible disc change. Set the bit - this */
1375                         /* may be used if there are filesystems using this device */
1376                         sdp->device->changed = 1;
1377                 }
1378         }
1379
1380         if (req->sense_len)
1381                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1382
1383         /* Rely on write phase to clean out srp status values, so no "else" */
1384
1385         /*
1386          * Free the request as soon as it is complete so that its resources
1387          * can be reused without waiting for userspace to read() the
1388          * result.  But keep the associated bio (if any) around until
1389          * blk_rq_unmap_user() can be called from user context.
1390          */
1391         srp->rq = NULL;
1392         scsi_req_free_cmd(scsi_req(rq));
1393         blk_mq_free_request(rq);
1394
1395         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1396         if (unlikely(srp->orphan)) {
1397                 if (sfp->keep_orphan)
1398                         srp->sg_io_owned = 0;
1399                 else
1400                         done = 0;
1401         }
1402         srp->done = done;
1403         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1404
1405         if (likely(done)) {
1406                 /* Now wake up any sg_read() that is waiting for this
1407                  * packet.
1408                  */
1409                 wake_up_interruptible(&sfp->read_wait);
1410                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1411                 kref_put(&sfp->f_ref, sg_remove_sfp);
1412         } else {
1413                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1414                 schedule_work(&srp->ew.work);
1415         }
1416 }
1417
1418 static const struct file_operations sg_fops = {
1419         .owner = THIS_MODULE,
1420         .read = sg_read,
1421         .write = sg_write,
1422         .poll = sg_poll,
1423         .unlocked_ioctl = sg_ioctl,
1424         .compat_ioctl = compat_ptr_ioctl,
1425         .open = sg_open,
1426         .mmap = sg_mmap,
1427         .release = sg_release,
1428         .fasync = sg_fasync,
1429         .llseek = no_llseek,
1430 };
1431
1432 static struct class *sg_sysfs_class;
1433
1434 static int sg_sysfs_valid = 0;
1435
1436 static Sg_device *
1437 sg_alloc(struct scsi_device *scsidp)
1438 {
1439         struct request_queue *q = scsidp->request_queue;
1440         Sg_device *sdp;
1441         unsigned long iflags;
1442         int error;
1443         u32 k;
1444
1445         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1446         if (!sdp) {
1447                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1448                             "failure\n", __func__);
1449                 return ERR_PTR(-ENOMEM);
1450         }
1451
1452         idr_preload(GFP_KERNEL);
1453         write_lock_irqsave(&sg_index_lock, iflags);
1454
1455         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1456         if (error < 0) {
1457                 if (error == -ENOSPC) {
1458                         sdev_printk(KERN_WARNING, scsidp,
1459                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1460                                     scsidp->type, SG_MAX_DEVS - 1);
1461                         error = -ENODEV;
1462                 } else {
1463                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1464                                     "allocation Sg_device failure: %d\n",
1465                                     __func__, error);
1466                 }
1467                 goto out_unlock;
1468         }
1469         k = error;
1470
1471         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1472                                         "sg_alloc: dev=%d \n", k));
1473         sprintf(sdp->name, "sg%d", k);
1474         sdp->device = scsidp;
1475         mutex_init(&sdp->open_rel_lock);
1476         INIT_LIST_HEAD(&sdp->sfds);
1477         init_waitqueue_head(&sdp->open_wait);
1478         atomic_set(&sdp->detaching, 0);
1479         rwlock_init(&sdp->sfd_lock);
1480         sdp->sg_tablesize = queue_max_segments(q);
1481         sdp->index = k;
1482         kref_init(&sdp->d_ref);
1483         error = 0;
1484
1485 out_unlock:
1486         write_unlock_irqrestore(&sg_index_lock, iflags);
1487         idr_preload_end();
1488
1489         if (error) {
1490                 kfree(sdp);
1491                 return ERR_PTR(error);
1492         }
1493         return sdp;
1494 }
1495
1496 static int
1497 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1498 {
1499         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1500         Sg_device *sdp = NULL;
1501         struct cdev * cdev = NULL;
1502         int error;
1503         unsigned long iflags;
1504
1505         error = -ENOMEM;
1506         cdev = cdev_alloc();
1507         if (!cdev) {
1508                 pr_warn("%s: cdev_alloc failed\n", __func__);
1509                 goto out;
1510         }
1511         cdev->owner = THIS_MODULE;
1512         cdev->ops = &sg_fops;
1513
1514         sdp = sg_alloc(scsidp);
1515         if (IS_ERR(sdp)) {
1516                 pr_warn("%s: sg_alloc failed\n", __func__);
1517                 error = PTR_ERR(sdp);
1518                 goto out;
1519         }
1520
1521         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1522         if (error)
1523                 goto cdev_add_err;
1524
1525         sdp->cdev = cdev;
1526         if (sg_sysfs_valid) {
1527                 struct device *sg_class_member;
1528
1529                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1530                                                 MKDEV(SCSI_GENERIC_MAJOR,
1531                                                       sdp->index),
1532                                                 sdp, "%s", sdp->name);
1533                 if (IS_ERR(sg_class_member)) {
1534                         pr_err("%s: device_create failed\n", __func__);
1535                         error = PTR_ERR(sg_class_member);
1536                         goto cdev_add_err;
1537                 }
1538                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1539                                           &sg_class_member->kobj, "generic");
1540                 if (error)
1541                         pr_err("%s: unable to make symlink 'generic' back "
1542                                "to sg%d\n", __func__, sdp->index);
1543         } else
1544                 pr_warn("%s: sg_sys Invalid\n", __func__);
1545
1546         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1547                     "type %d\n", sdp->index, scsidp->type);
1548
1549         dev_set_drvdata(cl_dev, sdp);
1550
1551         return 0;
1552
1553 cdev_add_err:
1554         write_lock_irqsave(&sg_index_lock, iflags);
1555         idr_remove(&sg_index_idr, sdp->index);
1556         write_unlock_irqrestore(&sg_index_lock, iflags);
1557         kfree(sdp);
1558
1559 out:
1560         if (cdev)
1561                 cdev_del(cdev);
1562         return error;
1563 }
1564
1565 static void
1566 sg_device_destroy(struct kref *kref)
1567 {
1568         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1569         unsigned long flags;
1570
1571         /* CAUTION!  Note that the device can still be found via idr_find()
1572          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1573          * any other cleanup.
1574          */
1575
1576         write_lock_irqsave(&sg_index_lock, flags);
1577         idr_remove(&sg_index_idr, sdp->index);
1578         write_unlock_irqrestore(&sg_index_lock, flags);
1579
1580         SCSI_LOG_TIMEOUT(3,
1581                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1582
1583         kfree(sdp);
1584 }
1585
1586 static void
1587 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1588 {
1589         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1590         Sg_device *sdp = dev_get_drvdata(cl_dev);
1591         unsigned long iflags;
1592         Sg_fd *sfp;
1593         int val;
1594
1595         if (!sdp)
1596                 return;
1597         /* want sdp->detaching non-zero as soon as possible */
1598         val = atomic_inc_return(&sdp->detaching);
1599         if (val > 1)
1600                 return; /* only want to do following once per device */
1601
1602         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1603                                       "%s\n", __func__));
1604
1605         read_lock_irqsave(&sdp->sfd_lock, iflags);
1606         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1607                 wake_up_interruptible_all(&sfp->read_wait);
1608                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1609         }
1610         wake_up_interruptible_all(&sdp->open_wait);
1611         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1612
1613         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1614         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1615         cdev_del(sdp->cdev);
1616         sdp->cdev = NULL;
1617
1618         kref_put(&sdp->d_ref, sg_device_destroy);
1619 }
1620
1621 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1622 module_param_named(def_reserved_size, def_reserved_size, int,
1623                    S_IRUGO | S_IWUSR);
1624 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1625
1626 MODULE_AUTHOR("Douglas Gilbert");
1627 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1628 MODULE_LICENSE("GPL");
1629 MODULE_VERSION(SG_VERSION_STR);
1630 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1631
1632 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1633                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1634 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1635 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1636
1637 #ifdef CONFIG_SYSCTL
1638 #include <linux/sysctl.h>
1639
1640 static struct ctl_table sg_sysctls[] = {
1641         {
1642                 .procname       = "sg-big-buff",
1643                 .data           = &sg_big_buff,
1644                 .maxlen         = sizeof(int),
1645                 .mode           = 0444,
1646                 .proc_handler   = proc_dointvec,
1647         },
1648         {}
1649 };
1650
1651 static struct ctl_table_header *hdr;
1652 static void register_sg_sysctls(void)
1653 {
1654         if (!hdr)
1655                 hdr = register_sysctl("kernel", sg_sysctls);
1656 }
1657
1658 static void unregister_sg_sysctls(void)
1659 {
1660         if (hdr)
1661                 unregister_sysctl_table(hdr);
1662 }
1663 #else
1664 #define register_sg_sysctls() do { } while (0)
1665 #define unregister_sg_sysctls() do { } while (0)
1666 #endif /* CONFIG_SYSCTL */
1667
1668 static int __init
1669 init_sg(void)
1670 {
1671         int rc;
1672
1673         if (scatter_elem_sz < PAGE_SIZE) {
1674                 scatter_elem_sz = PAGE_SIZE;
1675                 scatter_elem_sz_prev = scatter_elem_sz;
1676         }
1677         if (def_reserved_size >= 0)
1678                 sg_big_buff = def_reserved_size;
1679         else
1680                 def_reserved_size = sg_big_buff;
1681
1682         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1683                                     SG_MAX_DEVS, "sg");
1684         if (rc)
1685                 return rc;
1686         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1687         if ( IS_ERR(sg_sysfs_class) ) {
1688                 rc = PTR_ERR(sg_sysfs_class);
1689                 goto err_out;
1690         }
1691         sg_sysfs_valid = 1;
1692         rc = scsi_register_interface(&sg_interface);
1693         if (0 == rc) {
1694 #ifdef CONFIG_SCSI_PROC_FS
1695                 sg_proc_init();
1696 #endif                          /* CONFIG_SCSI_PROC_FS */
1697                 return 0;
1698         }
1699         class_destroy(sg_sysfs_class);
1700         register_sg_sysctls();
1701 err_out:
1702         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1703         return rc;
1704 }
1705
1706 static void __exit
1707 exit_sg(void)
1708 {
1709         unregister_sg_sysctls();
1710 #ifdef CONFIG_SCSI_PROC_FS
1711         remove_proc_subtree("scsi/sg", NULL);
1712 #endif                          /* CONFIG_SCSI_PROC_FS */
1713         scsi_unregister_interface(&sg_interface);
1714         class_destroy(sg_sysfs_class);
1715         sg_sysfs_valid = 0;
1716         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1717                                  SG_MAX_DEVS);
1718         idr_destroy(&sg_index_idr);
1719 }
1720
1721 static int
1722 sg_start_req(Sg_request *srp, unsigned char *cmd)
1723 {
1724         int res;
1725         struct request *rq;
1726         struct scsi_request *req;
1727         Sg_fd *sfp = srp->parentfp;
1728         sg_io_hdr_t *hp = &srp->header;
1729         int dxfer_len = (int) hp->dxfer_len;
1730         int dxfer_dir = hp->dxfer_direction;
1731         unsigned int iov_count = hp->iovec_count;
1732         Sg_scatter_hold *req_schp = &srp->data;
1733         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1734         struct request_queue *q = sfp->parentdp->device->request_queue;
1735         struct rq_map_data *md, map_data;
1736         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1737         unsigned char *long_cmdp = NULL;
1738
1739         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1740                                       "sg_start_req: dxfer_len=%d\n",
1741                                       dxfer_len));
1742
1743         if (hp->cmd_len > BLK_MAX_CDB) {
1744                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1745                 if (!long_cmdp)
1746                         return -ENOMEM;
1747         }
1748
1749         /*
1750          * NOTE
1751          *
1752          * With scsi-mq enabled, there are a fixed number of preallocated
1753          * requests equal in number to shost->can_queue.  If all of the
1754          * preallocated requests are already in use, then scsi_alloc_request()
1755          * will sleep until an active command completes, freeing up a request.
1756          * Although waiting in an asynchronous interface is less than ideal, we
1757          * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1758          * not expect an EWOULDBLOCK from this condition.
1759          */
1760         rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1761                         REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1762         if (IS_ERR(rq)) {
1763                 kfree(long_cmdp);
1764                 return PTR_ERR(rq);
1765         }
1766         req = scsi_req(rq);
1767
1768         if (hp->cmd_len > BLK_MAX_CDB)
1769                 req->cmd = long_cmdp;
1770         memcpy(req->cmd, cmd, hp->cmd_len);
1771         req->cmd_len = hp->cmd_len;
1772
1773         srp->rq = rq;
1774         rq->end_io_data = srp;
1775         req->retries = SG_DEFAULT_RETRIES;
1776
1777         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1778                 return 0;
1779
1780         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1781             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1782             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1783                 md = NULL;
1784         else
1785                 md = &map_data;
1786
1787         if (md) {
1788                 mutex_lock(&sfp->f_mutex);
1789                 if (dxfer_len <= rsv_schp->bufflen &&
1790                     !sfp->res_in_use) {
1791                         sfp->res_in_use = 1;
1792                         sg_link_reserve(sfp, srp, dxfer_len);
1793                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1794                         res = -EBUSY; /* sfp->res_in_use == 1 */
1795                         if (dxfer_len > rsv_schp->bufflen)
1796                                 res = -ENOMEM;
1797                         mutex_unlock(&sfp->f_mutex);
1798                         return res;
1799                 } else {
1800                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1801                         if (res) {
1802                                 mutex_unlock(&sfp->f_mutex);
1803                                 return res;
1804                         }
1805                 }
1806                 mutex_unlock(&sfp->f_mutex);
1807
1808                 md->pages = req_schp->pages;
1809                 md->page_order = req_schp->page_order;
1810                 md->nr_entries = req_schp->k_use_sg;
1811                 md->offset = 0;
1812                 md->null_mapped = hp->dxferp ? 0 : 1;
1813                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1814                         md->from_user = 1;
1815                 else
1816                         md->from_user = 0;
1817         }
1818
1819         if (iov_count) {
1820                 struct iovec *iov = NULL;
1821                 struct iov_iter i;
1822
1823                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1824                 if (res < 0)
1825                         return res;
1826
1827                 iov_iter_truncate(&i, hp->dxfer_len);
1828                 if (!iov_iter_count(&i)) {
1829                         kfree(iov);
1830                         return -EINVAL;
1831                 }
1832
1833                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1834                 kfree(iov);
1835         } else
1836                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1837                                       hp->dxfer_len, GFP_ATOMIC);
1838
1839         if (!res) {
1840                 srp->bio = rq->bio;
1841
1842                 if (!md) {
1843                         req_schp->dio_in_use = 1;
1844                         hp->info |= SG_INFO_DIRECT_IO;
1845                 }
1846         }
1847         return res;
1848 }
1849
1850 static int
1851 sg_finish_rem_req(Sg_request *srp)
1852 {
1853         int ret = 0;
1854
1855         Sg_fd *sfp = srp->parentfp;
1856         Sg_scatter_hold *req_schp = &srp->data;
1857
1858         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1859                                       "sg_finish_rem_req: res_used=%d\n",
1860                                       (int) srp->res_used));
1861         if (srp->bio)
1862                 ret = blk_rq_unmap_user(srp->bio);
1863
1864         if (srp->rq) {
1865                 scsi_req_free_cmd(scsi_req(srp->rq));
1866                 blk_mq_free_request(srp->rq);
1867         }
1868
1869         if (srp->res_used)
1870                 sg_unlink_reserve(sfp, srp);
1871         else
1872                 sg_remove_scat(sfp, req_schp);
1873
1874         return ret;
1875 }
1876
1877 static int
1878 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1879 {
1880         int sg_bufflen = tablesize * sizeof(struct page *);
1881         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1882
1883         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1884         if (!schp->pages)
1885                 return -ENOMEM;
1886         schp->sglist_len = sg_bufflen;
1887         return tablesize;       /* number of scat_gath elements allocated */
1888 }
1889
1890 static int
1891 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1892 {
1893         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1894         int sg_tablesize = sfp->parentdp->sg_tablesize;
1895         int blk_size = buff_size, order;
1896         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1897
1898         if (blk_size < 0)
1899                 return -EFAULT;
1900         if (0 == blk_size)
1901                 ++blk_size;     /* don't know why */
1902         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1903         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1904         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1905                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1906                 buff_size, blk_size));
1907
1908         /* N.B. ret_sz carried into this block ... */
1909         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1910         if (mx_sc_elems < 0)
1911                 return mx_sc_elems;     /* most likely -ENOMEM */
1912
1913         num = scatter_elem_sz;
1914         if (unlikely(num != scatter_elem_sz_prev)) {
1915                 if (num < PAGE_SIZE) {
1916                         scatter_elem_sz = PAGE_SIZE;
1917                         scatter_elem_sz_prev = PAGE_SIZE;
1918                 } else
1919                         scatter_elem_sz_prev = num;
1920         }
1921
1922         order = get_order(num);
1923 retry:
1924         ret_sz = 1 << (PAGE_SHIFT + order);
1925
1926         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1927              k++, rem_sz -= ret_sz) {
1928
1929                 num = (rem_sz > scatter_elem_sz_prev) ?
1930                         scatter_elem_sz_prev : rem_sz;
1931
1932                 schp->pages[k] = alloc_pages(gfp_mask, order);
1933                 if (!schp->pages[k])
1934                         goto out;
1935
1936                 if (num == scatter_elem_sz_prev) {
1937                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1938                                 scatter_elem_sz = ret_sz;
1939                                 scatter_elem_sz_prev = ret_sz;
1940                         }
1941                 }
1942
1943                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1944                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1945                                  k, num, ret_sz));
1946         }               /* end of for loop */
1947
1948         schp->page_order = order;
1949         schp->k_use_sg = k;
1950         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1951                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1952                          k, rem_sz));
1953
1954         schp->bufflen = blk_size;
1955         if (rem_sz > 0) /* must have failed */
1956                 return -ENOMEM;
1957         return 0;
1958 out:
1959         for (i = 0; i < k; i++)
1960                 __free_pages(schp->pages[i], order);
1961
1962         if (--order >= 0)
1963                 goto retry;
1964
1965         return -ENOMEM;
1966 }
1967
1968 static void
1969 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1970 {
1971         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1972                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1973         if (schp->pages && schp->sglist_len > 0) {
1974                 if (!schp->dio_in_use) {
1975                         int k;
1976
1977                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1978                                 SCSI_LOG_TIMEOUT(5,
1979                                         sg_printk(KERN_INFO, sfp->parentdp,
1980                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1981                                         k, schp->pages[k]));
1982                                 __free_pages(schp->pages[k], schp->page_order);
1983                         }
1984
1985                         kfree(schp->pages);
1986                 }
1987         }
1988         memset(schp, 0, sizeof (*schp));
1989 }
1990
1991 static int
1992 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1993 {
1994         Sg_scatter_hold *schp = &srp->data;
1995         int k, num;
1996
1997         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1998                          "sg_read_oxfer: num_read_xfer=%d\n",
1999                          num_read_xfer));
2000         if ((!outp) || (num_read_xfer <= 0))
2001                 return 0;
2002
2003         num = 1 << (PAGE_SHIFT + schp->page_order);
2004         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
2005                 if (num > num_read_xfer) {
2006                         if (copy_to_user(outp, page_address(schp->pages[k]),
2007                                            num_read_xfer))
2008                                 return -EFAULT;
2009                         break;
2010                 } else {
2011                         if (copy_to_user(outp, page_address(schp->pages[k]),
2012                                            num))
2013                                 return -EFAULT;
2014                         num_read_xfer -= num;
2015                         if (num_read_xfer <= 0)
2016                                 break;
2017                         outp += num;
2018                 }
2019         }
2020
2021         return 0;
2022 }
2023
2024 static void
2025 sg_build_reserve(Sg_fd * sfp, int req_size)
2026 {
2027         Sg_scatter_hold *schp = &sfp->reserve;
2028
2029         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2030                          "sg_build_reserve: req_size=%d\n", req_size));
2031         do {
2032                 if (req_size < PAGE_SIZE)
2033                         req_size = PAGE_SIZE;
2034                 if (0 == sg_build_indirect(schp, sfp, req_size))
2035                         return;
2036                 else
2037                         sg_remove_scat(sfp, schp);
2038                 req_size >>= 1; /* divide by 2 */
2039         } while (req_size > (PAGE_SIZE / 2));
2040 }
2041
2042 static void
2043 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2044 {
2045         Sg_scatter_hold *req_schp = &srp->data;
2046         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2047         int k, num, rem;
2048
2049         srp->res_used = 1;
2050         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2051                          "sg_link_reserve: size=%d\n", size));
2052         rem = size;
2053
2054         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2055         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2056                 if (rem <= num) {
2057                         req_schp->k_use_sg = k + 1;
2058                         req_schp->sglist_len = rsv_schp->sglist_len;
2059                         req_schp->pages = rsv_schp->pages;
2060
2061                         req_schp->bufflen = size;
2062                         req_schp->page_order = rsv_schp->page_order;
2063                         break;
2064                 } else
2065                         rem -= num;
2066         }
2067
2068         if (k >= rsv_schp->k_use_sg)
2069                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2070                                  "sg_link_reserve: BAD size\n"));
2071 }
2072
2073 static void
2074 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2075 {
2076         Sg_scatter_hold *req_schp = &srp->data;
2077
2078         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2079                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2080                                       (int) req_schp->k_use_sg));
2081         req_schp->k_use_sg = 0;
2082         req_schp->bufflen = 0;
2083         req_schp->pages = NULL;
2084         req_schp->page_order = 0;
2085         req_schp->sglist_len = 0;
2086         srp->res_used = 0;
2087         /* Called without mutex lock to avoid deadlock */
2088         sfp->res_in_use = 0;
2089 }
2090
2091 static Sg_request *
2092 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2093 {
2094         Sg_request *resp;
2095         unsigned long iflags;
2096
2097         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2098         list_for_each_entry(resp, &sfp->rq_list, entry) {
2099                 /* look for requests that are ready + not SG_IO owned */
2100                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2101                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2102                         resp->done = 2; /* guard against other readers */
2103                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2104                         return resp;
2105                 }
2106         }
2107         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2108         return NULL;
2109 }
2110
2111 /* always adds to end of list */
2112 static Sg_request *
2113 sg_add_request(Sg_fd * sfp)
2114 {
2115         int k;
2116         unsigned long iflags;
2117         Sg_request *rp = sfp->req_arr;
2118
2119         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2120         if (!list_empty(&sfp->rq_list)) {
2121                 if (!sfp->cmd_q)
2122                         goto out_unlock;
2123
2124                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2125                         if (!rp->parentfp)
2126                                 break;
2127                 }
2128                 if (k >= SG_MAX_QUEUE)
2129                         goto out_unlock;
2130         }
2131         memset(rp, 0, sizeof (Sg_request));
2132         rp->parentfp = sfp;
2133         rp->header.duration = jiffies_to_msecs(jiffies);
2134         list_add_tail(&rp->entry, &sfp->rq_list);
2135         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2136         return rp;
2137 out_unlock:
2138         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2139         return NULL;
2140 }
2141
2142 /* Return of 1 for found; 0 for not found */
2143 static int
2144 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2145 {
2146         unsigned long iflags;
2147         int res = 0;
2148
2149         if (!sfp || !srp || list_empty(&sfp->rq_list))
2150                 return res;
2151         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2152         if (!list_empty(&srp->entry)) {
2153                 list_del(&srp->entry);
2154                 srp->parentfp = NULL;
2155                 res = 1;
2156         }
2157         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2158         return res;
2159 }
2160
2161 static Sg_fd *
2162 sg_add_sfp(Sg_device * sdp)
2163 {
2164         Sg_fd *sfp;
2165         unsigned long iflags;
2166         int bufflen;
2167
2168         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2169         if (!sfp)
2170                 return ERR_PTR(-ENOMEM);
2171
2172         init_waitqueue_head(&sfp->read_wait);
2173         rwlock_init(&sfp->rq_list_lock);
2174         INIT_LIST_HEAD(&sfp->rq_list);
2175         kref_init(&sfp->f_ref);
2176         mutex_init(&sfp->f_mutex);
2177         sfp->timeout = SG_DEFAULT_TIMEOUT;
2178         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2179         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2180         sfp->cmd_q = SG_DEF_COMMAND_Q;
2181         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2182         sfp->parentdp = sdp;
2183         write_lock_irqsave(&sdp->sfd_lock, iflags);
2184         if (atomic_read(&sdp->detaching)) {
2185                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2186                 kfree(sfp);
2187                 return ERR_PTR(-ENODEV);
2188         }
2189         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2190         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2191         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2192                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2193         if (unlikely(sg_big_buff != def_reserved_size))
2194                 sg_big_buff = def_reserved_size;
2195
2196         bufflen = min_t(int, sg_big_buff,
2197                         max_sectors_bytes(sdp->device->request_queue));
2198         sg_build_reserve(sfp, bufflen);
2199         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2200                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2201                                       sfp->reserve.bufflen,
2202                                       sfp->reserve.k_use_sg));
2203
2204         kref_get(&sdp->d_ref);
2205         __module_get(THIS_MODULE);
2206         return sfp;
2207 }
2208
2209 static void
2210 sg_remove_sfp_usercontext(struct work_struct *work)
2211 {
2212         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2213         struct sg_device *sdp = sfp->parentdp;
2214         Sg_request *srp;
2215         unsigned long iflags;
2216
2217         /* Cleanup any responses which were never read(). */
2218         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2219         while (!list_empty(&sfp->rq_list)) {
2220                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2221                 sg_finish_rem_req(srp);
2222                 list_del(&srp->entry);
2223                 srp->parentfp = NULL;
2224         }
2225         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2226
2227         if (sfp->reserve.bufflen > 0) {
2228                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2229                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2230                                 (int) sfp->reserve.bufflen,
2231                                 (int) sfp->reserve.k_use_sg));
2232                 sg_remove_scat(sfp, &sfp->reserve);
2233         }
2234
2235         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2236                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2237         kfree(sfp);
2238
2239         scsi_device_put(sdp->device);
2240         kref_put(&sdp->d_ref, sg_device_destroy);
2241         module_put(THIS_MODULE);
2242 }
2243
2244 static void
2245 sg_remove_sfp(struct kref *kref)
2246 {
2247         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2248         struct sg_device *sdp = sfp->parentdp;
2249         unsigned long iflags;
2250
2251         write_lock_irqsave(&sdp->sfd_lock, iflags);
2252         list_del(&sfp->sfd_siblings);
2253         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2254
2255         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2256         schedule_work(&sfp->ew.work);
2257 }
2258
2259 #ifdef CONFIG_SCSI_PROC_FS
2260 static int
2261 sg_idr_max_id(int id, void *p, void *data)
2262 {
2263         int *k = data;
2264
2265         if (*k < id)
2266                 *k = id;
2267
2268         return 0;
2269 }
2270
2271 static int
2272 sg_last_dev(void)
2273 {
2274         int k = -1;
2275         unsigned long iflags;
2276
2277         read_lock_irqsave(&sg_index_lock, iflags);
2278         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2279         read_unlock_irqrestore(&sg_index_lock, iflags);
2280         return k + 1;           /* origin 1 */
2281 }
2282 #endif
2283
2284 /* must be called with sg_index_lock held */
2285 static Sg_device *sg_lookup_dev(int dev)
2286 {
2287         return idr_find(&sg_index_idr, dev);
2288 }
2289
2290 static Sg_device *
2291 sg_get_dev(int dev)
2292 {
2293         struct sg_device *sdp;
2294         unsigned long flags;
2295
2296         read_lock_irqsave(&sg_index_lock, flags);
2297         sdp = sg_lookup_dev(dev);
2298         if (!sdp)
2299                 sdp = ERR_PTR(-ENXIO);
2300         else if (atomic_read(&sdp->detaching)) {
2301                 /* If sdp->detaching, then the refcount may already be 0, in
2302                  * which case it would be a bug to do kref_get().
2303                  */
2304                 sdp = ERR_PTR(-ENODEV);
2305         } else
2306                 kref_get(&sdp->d_ref);
2307         read_unlock_irqrestore(&sg_index_lock, flags);
2308
2309         return sdp;
2310 }
2311
2312 #ifdef CONFIG_SCSI_PROC_FS
2313 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2314
2315 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2316 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2317                                   size_t count, loff_t *off);
2318 static const struct proc_ops adio_proc_ops = {
2319         .proc_open      = sg_proc_single_open_adio,
2320         .proc_read      = seq_read,
2321         .proc_lseek     = seq_lseek,
2322         .proc_write     = sg_proc_write_adio,
2323         .proc_release   = single_release,
2324 };
2325
2326 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2327 static ssize_t sg_proc_write_dressz(struct file *filp,
2328                 const char __user *buffer, size_t count, loff_t *off);
2329 static const struct proc_ops dressz_proc_ops = {
2330         .proc_open      = sg_proc_single_open_dressz,
2331         .proc_read      = seq_read,
2332         .proc_lseek     = seq_lseek,
2333         .proc_write     = sg_proc_write_dressz,
2334         .proc_release   = single_release,
2335 };
2336
2337 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2338 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2339 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2340 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2341 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2342 static void dev_seq_stop(struct seq_file *s, void *v);
2343 static const struct seq_operations dev_seq_ops = {
2344         .start = dev_seq_start,
2345         .next  = dev_seq_next,
2346         .stop  = dev_seq_stop,
2347         .show  = sg_proc_seq_show_dev,
2348 };
2349
2350 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2351 static const struct seq_operations devstrs_seq_ops = {
2352         .start = dev_seq_start,
2353         .next  = dev_seq_next,
2354         .stop  = dev_seq_stop,
2355         .show  = sg_proc_seq_show_devstrs,
2356 };
2357
2358 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2359 static const struct seq_operations debug_seq_ops = {
2360         .start = dev_seq_start,
2361         .next  = dev_seq_next,
2362         .stop  = dev_seq_stop,
2363         .show  = sg_proc_seq_show_debug,
2364 };
2365
2366 static int
2367 sg_proc_init(void)
2368 {
2369         struct proc_dir_entry *p;
2370
2371         p = proc_mkdir("scsi/sg", NULL);
2372         if (!p)
2373                 return 1;
2374
2375         proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2376         proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2377         proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2378         proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2379         proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2380         proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2381         proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2382         return 0;
2383 }
2384
2385
2386 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2387 {
2388         seq_printf(s, "%d\n", *((int *)s->private));
2389         return 0;
2390 }
2391
2392 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2393 {
2394         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2395 }
2396
2397 static ssize_t
2398 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2399                    size_t count, loff_t *off)
2400 {
2401         int err;
2402         unsigned long num;
2403
2404         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2405                 return -EACCES;
2406         err = kstrtoul_from_user(buffer, count, 0, &num);
2407         if (err)
2408                 return err;
2409         sg_allow_dio = num ? 1 : 0;
2410         return count;
2411 }
2412
2413 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2414 {
2415         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2416 }
2417
2418 static ssize_t
2419 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2420                      size_t count, loff_t *off)
2421 {
2422         int err;
2423         unsigned long k = ULONG_MAX;
2424
2425         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2426                 return -EACCES;
2427
2428         err = kstrtoul_from_user(buffer, count, 0, &k);
2429         if (err)
2430                 return err;
2431         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2432                 sg_big_buff = k;
2433                 return count;
2434         }
2435         return -ERANGE;
2436 }
2437
2438 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2439 {
2440         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2441                    sg_version_date);
2442         return 0;
2443 }
2444
2445 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2446 {
2447         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2448         return 0;
2449 }
2450
2451 struct sg_proc_deviter {
2452         loff_t  index;
2453         size_t  max;
2454 };
2455
2456 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2457 {
2458         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2459
2460         s->private = it;
2461         if (! it)
2462                 return NULL;
2463
2464         it->index = *pos;
2465         it->max = sg_last_dev();
2466         if (it->index >= it->max)
2467                 return NULL;
2468         return it;
2469 }
2470
2471 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2472 {
2473         struct sg_proc_deviter * it = s->private;
2474
2475         *pos = ++it->index;
2476         return (it->index < it->max) ? it : NULL;
2477 }
2478
2479 static void dev_seq_stop(struct seq_file *s, void *v)
2480 {
2481         kfree(s->private);
2482 }
2483
2484 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2485 {
2486         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2487         Sg_device *sdp;
2488         struct scsi_device *scsidp;
2489         unsigned long iflags;
2490
2491         read_lock_irqsave(&sg_index_lock, iflags);
2492         sdp = it ? sg_lookup_dev(it->index) : NULL;
2493         if ((NULL == sdp) || (NULL == sdp->device) ||
2494             (atomic_read(&sdp->detaching)))
2495                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2496         else {
2497                 scsidp = sdp->device;
2498                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2499                               scsidp->host->host_no, scsidp->channel,
2500                               scsidp->id, scsidp->lun, (int) scsidp->type,
2501                               1,
2502                               (int) scsidp->queue_depth,
2503                               (int) scsi_device_busy(scsidp),
2504                               (int) scsi_device_online(scsidp));
2505         }
2506         read_unlock_irqrestore(&sg_index_lock, iflags);
2507         return 0;
2508 }
2509
2510 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2511 {
2512         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2513         Sg_device *sdp;
2514         struct scsi_device *scsidp;
2515         unsigned long iflags;
2516
2517         read_lock_irqsave(&sg_index_lock, iflags);
2518         sdp = it ? sg_lookup_dev(it->index) : NULL;
2519         scsidp = sdp ? sdp->device : NULL;
2520         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2521                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2522                            scsidp->vendor, scsidp->model, scsidp->rev);
2523         else
2524                 seq_puts(s, "<no active device>\n");
2525         read_unlock_irqrestore(&sg_index_lock, iflags);
2526         return 0;
2527 }
2528
2529 /* must be called while holding sg_index_lock */
2530 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2531 {
2532         int k, new_interface, blen, usg;
2533         Sg_request *srp;
2534         Sg_fd *fp;
2535         const sg_io_hdr_t *hp;
2536         const char * cp;
2537         unsigned int ms;
2538
2539         k = 0;
2540         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2541                 k++;
2542                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2543                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2544                            "(res)sgat=%d low_dma=%d\n", k,
2545                            jiffies_to_msecs(fp->timeout),
2546                            fp->reserve.bufflen,
2547                            (int) fp->reserve.k_use_sg, 0);
2548                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2549                            (int) fp->cmd_q, (int) fp->force_packid,
2550                            (int) fp->keep_orphan);
2551                 list_for_each_entry(srp, &fp->rq_list, entry) {
2552                         hp = &srp->header;
2553                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2554                         if (srp->res_used) {
2555                                 if (new_interface &&
2556                                     (SG_FLAG_MMAP_IO & hp->flags))
2557                                         cp = "     mmap>> ";
2558                                 else
2559                                         cp = "     rb>> ";
2560                         } else {
2561                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2562                                         cp = "     dio>> ";
2563                                 else
2564                                         cp = "     ";
2565                         }
2566                         seq_puts(s, cp);
2567                         blen = srp->data.bufflen;
2568                         usg = srp->data.k_use_sg;
2569                         seq_puts(s, srp->done ?
2570                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2571                                   : "act:");
2572                         seq_printf(s, " id=%d blen=%d",
2573                                    srp->header.pack_id, blen);
2574                         if (srp->done)
2575                                 seq_printf(s, " dur=%d", hp->duration);
2576                         else {
2577                                 ms = jiffies_to_msecs(jiffies);
2578                                 seq_printf(s, " t_o/elap=%d/%d",
2579                                         (new_interface ? hp->timeout :
2580                                                   jiffies_to_msecs(fp->timeout)),
2581                                         (ms > hp->duration ? ms - hp->duration : 0));
2582                         }
2583                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2584                                    (int) srp->data.cmd_opcode);
2585                 }
2586                 if (list_empty(&fp->rq_list))
2587                         seq_puts(s, "     No requests active\n");
2588                 read_unlock(&fp->rq_list_lock);
2589         }
2590 }
2591
2592 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2593 {
2594         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2595         Sg_device *sdp;
2596         unsigned long iflags;
2597
2598         if (it && (0 == it->index))
2599                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2600                            (int)it->max, sg_big_buff);
2601
2602         read_lock_irqsave(&sg_index_lock, iflags);
2603         sdp = it ? sg_lookup_dev(it->index) : NULL;
2604         if (NULL == sdp)
2605                 goto skip;
2606         read_lock(&sdp->sfd_lock);
2607         if (!list_empty(&sdp->sfds)) {
2608                 seq_printf(s, " >>> device=%s ", sdp->name);
2609                 if (atomic_read(&sdp->detaching))
2610                         seq_puts(s, "detaching pending close ");
2611                 else if (sdp->device) {
2612                         struct scsi_device *scsidp = sdp->device;
2613
2614                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2615                                    scsidp->host->host_no,
2616                                    scsidp->channel, scsidp->id,
2617                                    scsidp->lun,
2618                                    scsidp->host->hostt->emulated);
2619                 }
2620                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2621                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2622                 sg_proc_debug_helper(s, sdp);
2623         }
2624         read_unlock(&sdp->sfd_lock);
2625 skip:
2626         read_unlock_irqrestore(&sg_index_lock, iflags);
2627         return 0;
2628 }
2629
2630 #endif                          /* CONFIG_SCSI_PROC_FS */
2631
2632 module_init(init_sg);
2633 module_exit(exit_sg);