Linux Audio

Check our new training course

Loading...
   1/*
   2 *  History:
   3 *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4 *           to allow user process control of SCSI devices.
   5 *  Development Sponsored by Killy Corp. NY NY
   6 *
   7 * Original driver (sg.c):
   8 *        Copyright (C) 1992 Lawrence Foard
   9 * Version 2 and 3 extensions to driver:
  10 *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11 *
  12 *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2, or (at your option)
  17 * any later version.
  18 *
  19 */
  20
  21static int sg_version_num = 30534;	/* 2 digits for each component */
  22#define SG_VERSION_STR "3.5.34"
  23
  24/*
  25 *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26 *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27 *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28 *        (otherwise the macros compile to empty statements).
  29 *
  30 */
  31#include <linux/module.h>
  32
  33#include <linux/fs.h>
  34#include <linux/kernel.h>
  35#include <linux/sched.h>
  36#include <linux/string.h>
  37#include <linux/mm.h>
  38#include <linux/errno.h>
  39#include <linux/mtio.h>
  40#include <linux/ioctl.h>
  41#include <linux/slab.h>
  42#include <linux/fcntl.h>
  43#include <linux/init.h>
  44#include <linux/poll.h>
  45#include <linux/moduleparam.h>
  46#include <linux/cdev.h>
  47#include <linux/idr.h>
  48#include <linux/seq_file.h>
  49#include <linux/blkdev.h>
  50#include <linux/delay.h>
  51#include <linux/blktrace_api.h>
  52#include <linux/mutex.h>
  53#include <linux/ratelimit.h>
  54
  55#include "scsi.h"
  56#include <scsi/scsi_dbg.h>
  57#include <scsi/scsi_host.h>
  58#include <scsi/scsi_driver.h>
  59#include <scsi/scsi_ioctl.h>
  60#include <scsi/sg.h>
  61
  62#include "scsi_logging.h"
  63
  64#ifdef CONFIG_SCSI_PROC_FS
  65#include <linux/proc_fs.h>
  66static char *sg_version_date = "20061027";
  67
  68static int sg_proc_init(void);
  69static void sg_proc_cleanup(void);
  70#endif
  71
  72#define SG_ALLOW_DIO_DEF 0
  73
  74#define SG_MAX_DEVS 32768
  75
  76/*
  77 * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  78 * Then when using 32 bit integers x * m may overflow during the calculation.
  79 * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  80 * calculates the same, but prevents the overflow when both m and d
  81 * are "small" numbers (like HZ and USER_HZ).
  82 * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  83 * in 32 bits.
  84 */
  85#define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  86
  87#define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  88
  89int sg_big_buff = SG_DEF_RESERVED_SIZE;
  90/* N.B. This variable is readable and writeable via
  91   /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  92   of this size (or less if there is not enough memory) will be reserved
  93   for use by this file descriptor. [Deprecated usage: this variable is also
  94   readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  95   the kernel (i.e. it is not a module).] */
  96static int def_reserved_size = -1;	/* picks up init parameter */
  97static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  98
  99static int scatter_elem_sz = SG_SCATTER_SZ;
 100static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 101
 102#define SG_SECTOR_SZ 512
 103
 104static int sg_add(struct device *, struct class_interface *);
 105static void sg_remove(struct device *, struct class_interface *);
 106
 107static DEFINE_SPINLOCK(sg_open_exclusive_lock);
 108
 109static DEFINE_IDR(sg_index_idr);
 110static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
 111							   file descriptor list for device */
 112
 113static struct class_interface sg_interface = {
 114	.add_dev	= sg_add,
 115	.remove_dev	= sg_remove,
 116};
 117
 118typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 119	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 120	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 121	unsigned bufflen;	/* Size of (aggregate) data buffer */
 122	struct page **pages;
 123	int page_order;
 124	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
 125	unsigned char cmd_opcode; /* first byte of command */
 126} Sg_scatter_hold;
 127
 128struct sg_device;		/* forward declarations */
 129struct sg_fd;
 130
 131typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
 132	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
 133	struct sg_fd *parentfp;	/* NULL -> not in use */
 134	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
 135	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
 136	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 137	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
 138	char orphan;		/* 1 -> drop on sight, 0 -> normal */
 139	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
 140	/* done protected by rq_list_lock */
 141	char done;		/* 0->before bh, 1->before read, 2->read */
 142	struct request *rq;
 143	struct bio *bio;
 144	struct execute_work ew;
 145} Sg_request;
 146
 147typedef struct sg_fd {		/* holds the state of a file descriptor */
 148	/* sfd_siblings is protected by sg_index_lock */
 149	struct list_head sfd_siblings;
 150	struct sg_device *parentdp;	/* owning device */
 151	wait_queue_head_t read_wait;	/* queue read until command done */
 152	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
 153	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
 154	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
 155	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
 156	unsigned save_scat_len;	/* original length of trunc. scat. element */
 157	Sg_request *headrp;	/* head of request slist, NULL->empty */
 158	struct fasync_struct *async_qp;	/* used by asynchronous notification */
 159	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
 160	char low_dma;		/* as in parent but possibly overridden to 1 */
 161	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
 162	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
 163	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
 164	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
 165	char mmap_called;	/* 0 -> mmap() never called on this fd */
 166	struct kref f_ref;
 167	struct execute_work ew;
 168} Sg_fd;
 169
 170typedef struct sg_device { /* holds the state of each scsi generic device */
 171	struct scsi_device *device;
 172	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
 173	int sg_tablesize;	/* adapter's max scatter-gather table size */
 174	u32 index;		/* device index number */
 175	/* sfds is protected by sg_index_lock */
 176	struct list_head sfds;
 177	volatile char detached;	/* 0->attached, 1->detached pending removal */
 178	/* exclude protected by sg_open_exclusive_lock */
 179	char exclude;		/* opened for exclusive access */
 180	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 181	struct gendisk *disk;
 182	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 183	struct kref d_ref;
 184} Sg_device;
 185
 186/* tasklet or soft irq callback */
 187static void sg_rq_end_io(struct request *rq, int uptodate);
 188static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 189static int sg_finish_rem_req(Sg_request * srp);
 190static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 191static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 192			   Sg_request * srp);
 193static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 194			const char __user *buf, size_t count, int blocking,
 195			int read_only, int sg_io_owned, Sg_request **o_srp);
 196static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 197			   unsigned char *cmnd, int timeout, int blocking);
 198static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 199static void sg_remove_scat(Sg_scatter_hold * schp);
 200static void sg_build_reserve(Sg_fd * sfp, int req_size);
 201static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 202static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 203static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 204static void sg_remove_sfp(struct kref *);
 205static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 206static Sg_request *sg_add_request(Sg_fd * sfp);
 207static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 208static int sg_res_in_use(Sg_fd * sfp);
 209static Sg_device *sg_get_dev(int dev);
 210static void sg_put_dev(Sg_device *sdp);
 211
 212#define SZ_SG_HEADER sizeof(struct sg_header)
 213#define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 214#define SZ_SG_IOVEC sizeof(sg_iovec_t)
 215#define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 216
 217static int sg_allow_access(struct file *filp, unsigned char *cmd)
 218{
 219	struct sg_fd *sfp = filp->private_data;
 220
 221	if (sfp->parentdp->device->type == TYPE_SCANNER)
 222		return 0;
 223
 224	return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 225}
 226
 227static int get_exclude(Sg_device *sdp)
 228{
 229	unsigned long flags;
 230	int ret;
 231
 232	spin_lock_irqsave(&sg_open_exclusive_lock, flags);
 233	ret = sdp->exclude;
 234	spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
 235	return ret;
 236}
 237
 238static int set_exclude(Sg_device *sdp, char val)
 239{
 240	unsigned long flags;
 241
 242	spin_lock_irqsave(&sg_open_exclusive_lock, flags);
 243	sdp->exclude = val;
 244	spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
 245	return val;
 246}
 247
 248static int sfds_list_empty(Sg_device *sdp)
 249{
 250	unsigned long flags;
 251	int ret;
 252
 253	read_lock_irqsave(&sg_index_lock, flags);
 254	ret = list_empty(&sdp->sfds);
 255	read_unlock_irqrestore(&sg_index_lock, flags);
 256	return ret;
 257}
 258
 259static int
 260sg_open(struct inode *inode, struct file *filp)
 261{
 262	int dev = iminor(inode);
 263	int flags = filp->f_flags;
 264	struct request_queue *q;
 265	Sg_device *sdp;
 266	Sg_fd *sfp;
 267	int res;
 268	int retval;
 269
 270	nonseekable_open(inode, filp);
 271	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 272	sdp = sg_get_dev(dev);
 273	if (IS_ERR(sdp)) {
 274		retval = PTR_ERR(sdp);
 275		sdp = NULL;
 276		goto sg_put;
 277	}
 278
 279	/* This driver's module count bumped by fops_get in <linux/fs.h> */
 280	/* Prevent the device driver from vanishing while we sleep */
 281	retval = scsi_device_get(sdp->device);
 282	if (retval)
 283		goto sg_put;
 284
 285	retval = scsi_autopm_get_device(sdp->device);
 286	if (retval)
 287		goto sdp_put;
 288
 289	if (!((flags & O_NONBLOCK) ||
 290	      scsi_block_when_processing_errors(sdp->device))) {
 291		retval = -ENXIO;
 292		/* we are in error recovery for this device */
 293		goto error_out;
 294	}
 295
 296	if (flags & O_EXCL) {
 297		if (O_RDONLY == (flags & O_ACCMODE)) {
 298			retval = -EPERM; /* Can't lock it with read only access */
 299			goto error_out;
 300		}
 301		if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
 302			retval = -EBUSY;
 303			goto error_out;
 304		}
 305		res = wait_event_interruptible(sdp->o_excl_wait,
 306					   ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
 307		if (res) {
 308			retval = res;	/* -ERESTARTSYS because signal hit process */
 309			goto error_out;
 310		}
 311	} else if (get_exclude(sdp)) {	/* some other fd has an exclusive lock on dev */
 312		if (flags & O_NONBLOCK) {
 313			retval = -EBUSY;
 314			goto error_out;
 315		}
 316		res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
 317		if (res) {
 318			retval = res;	/* -ERESTARTSYS because signal hit process */
 319			goto error_out;
 320		}
 321	}
 322	if (sdp->detached) {
 323		retval = -ENODEV;
 324		goto error_out;
 325	}
 326	if (sfds_list_empty(sdp)) {	/* no existing opens on this device */
 327		sdp->sgdebug = 0;
 328		q = sdp->device->request_queue;
 329		sdp->sg_tablesize = queue_max_segments(q);
 330	}
 331	if ((sfp = sg_add_sfp(sdp, dev)))
 332		filp->private_data = sfp;
 333	else {
 334		if (flags & O_EXCL) {
 335			set_exclude(sdp, 0);	/* undo if error */
 336			wake_up_interruptible(&sdp->o_excl_wait);
 337		}
 338		retval = -ENOMEM;
 339		goto error_out;
 340	}
 341	retval = 0;
 342error_out:
 343	if (retval) {
 344		scsi_autopm_put_device(sdp->device);
 345sdp_put:
 346		scsi_device_put(sdp->device);
 347	}
 348sg_put:
 349	if (sdp)
 350		sg_put_dev(sdp);
 351	return retval;
 352}
 353
 354/* Following function was formerly called 'sg_close' */
 355static int
 356sg_release(struct inode *inode, struct file *filp)
 357{
 358	Sg_device *sdp;
 359	Sg_fd *sfp;
 360
 361	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 362		return -ENXIO;
 363	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 364
 365	set_exclude(sdp, 0);
 366	wake_up_interruptible(&sdp->o_excl_wait);
 367
 368	scsi_autopm_put_device(sdp->device);
 369	kref_put(&sfp->f_ref, sg_remove_sfp);
 370	return 0;
 371}
 372
 373static ssize_t
 374sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 375{
 376	Sg_device *sdp;
 377	Sg_fd *sfp;
 378	Sg_request *srp;
 379	int req_pack_id = -1;
 380	sg_io_hdr_t *hp;
 381	struct sg_header *old_hdr = NULL;
 382	int retval = 0;
 383
 384	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 385		return -ENXIO;
 386	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 387				   sdp->disk->disk_name, (int) count));
 388
 389	if (!access_ok(VERIFY_WRITE, buf, count))
 390		return -EFAULT;
 391	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 392		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 393		if (!old_hdr)
 394			return -ENOMEM;
 395		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 396			retval = -EFAULT;
 397			goto free_old_hdr;
 398		}
 399		if (old_hdr->reply_len < 0) {
 400			if (count >= SZ_SG_IO_HDR) {
 401				sg_io_hdr_t *new_hdr;
 402				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 403				if (!new_hdr) {
 404					retval = -ENOMEM;
 405					goto free_old_hdr;
 406				}
 407				retval =__copy_from_user
 408				    (new_hdr, buf, SZ_SG_IO_HDR);
 409				req_pack_id = new_hdr->pack_id;
 410				kfree(new_hdr);
 411				if (retval) {
 412					retval = -EFAULT;
 413					goto free_old_hdr;
 414				}
 415			}
 416		} else
 417			req_pack_id = old_hdr->pack_id;
 418	}
 419	srp = sg_get_rq_mark(sfp, req_pack_id);
 420	if (!srp) {		/* now wait on packet to arrive */
 421		if (sdp->detached) {
 422			retval = -ENODEV;
 423			goto free_old_hdr;
 424		}
 425		if (filp->f_flags & O_NONBLOCK) {
 426			retval = -EAGAIN;
 427			goto free_old_hdr;
 428		}
 429		retval = wait_event_interruptible(sfp->read_wait,
 430			(sdp->detached ||
 431			(srp = sg_get_rq_mark(sfp, req_pack_id))));
 432		if (sdp->detached) {
 433			retval = -ENODEV;
 434			goto free_old_hdr;
 435		}
 436		if (retval) {
 437			/* -ERESTARTSYS as signal hit process */
 438			goto free_old_hdr;
 439		}
 440	}
 441	if (srp->header.interface_id != '\0') {
 442		retval = sg_new_read(sfp, buf, count, srp);
 443		goto free_old_hdr;
 444	}
 445
 446	hp = &srp->header;
 447	if (old_hdr == NULL) {
 448		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 449		if (! old_hdr) {
 450			retval = -ENOMEM;
 451			goto free_old_hdr;
 452		}
 453	}
 454	memset(old_hdr, 0, SZ_SG_HEADER);
 455	old_hdr->reply_len = (int) hp->timeout;
 456	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 457	old_hdr->pack_id = hp->pack_id;
 458	old_hdr->twelve_byte =
 459	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 460	old_hdr->target_status = hp->masked_status;
 461	old_hdr->host_status = hp->host_status;
 462	old_hdr->driver_status = hp->driver_status;
 463	if ((CHECK_CONDITION & hp->masked_status) ||
 464	    (DRIVER_SENSE & hp->driver_status))
 465		memcpy(old_hdr->sense_buffer, srp->sense_b,
 466		       sizeof (old_hdr->sense_buffer));
 467	switch (hp->host_status) {
 468	/* This setup of 'result' is for backward compatibility and is best
 469	   ignored by the user who should use target, host + driver status */
 470	case DID_OK:
 471	case DID_PASSTHROUGH:
 472	case DID_SOFT_ERROR:
 473		old_hdr->result = 0;
 474		break;
 475	case DID_NO_CONNECT:
 476	case DID_BUS_BUSY:
 477	case DID_TIME_OUT:
 478		old_hdr->result = EBUSY;
 479		break;
 480	case DID_BAD_TARGET:
 481	case DID_ABORT:
 482	case DID_PARITY:
 483	case DID_RESET:
 484	case DID_BAD_INTR:
 485		old_hdr->result = EIO;
 486		break;
 487	case DID_ERROR:
 488		old_hdr->result = (srp->sense_b[0] == 0 && 
 489				  hp->masked_status == GOOD) ? 0 : EIO;
 490		break;
 491	default:
 492		old_hdr->result = EIO;
 493		break;
 494	}
 495
 496	/* Now copy the result back to the user buffer.  */
 497	if (count >= SZ_SG_HEADER) {
 498		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 499			retval = -EFAULT;
 500			goto free_old_hdr;
 501		}
 502		buf += SZ_SG_HEADER;
 503		if (count > old_hdr->reply_len)
 504			count = old_hdr->reply_len;
 505		if (count > SZ_SG_HEADER) {
 506			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 507				retval = -EFAULT;
 508				goto free_old_hdr;
 509			}
 510		}
 511	} else
 512		count = (old_hdr->result == 0) ? 0 : -EIO;
 513	sg_finish_rem_req(srp);
 514	retval = count;
 515free_old_hdr:
 516	kfree(old_hdr);
 517	return retval;
 518}
 519
 520static ssize_t
 521sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 522{
 523	sg_io_hdr_t *hp = &srp->header;
 524	int err = 0;
 525	int len;
 526
 527	if (count < SZ_SG_IO_HDR) {
 528		err = -EINVAL;
 529		goto err_out;
 530	}
 531	hp->sb_len_wr = 0;
 532	if ((hp->mx_sb_len > 0) && hp->sbp) {
 533		if ((CHECK_CONDITION & hp->masked_status) ||
 534		    (DRIVER_SENSE & hp->driver_status)) {
 535			int sb_len = SCSI_SENSE_BUFFERSIZE;
 536			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 537			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
 538			len = (len > sb_len) ? sb_len : len;
 539			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 540				err = -EFAULT;
 541				goto err_out;
 542			}
 543			hp->sb_len_wr = len;
 544		}
 545	}
 546	if (hp->masked_status || hp->host_status || hp->driver_status)
 547		hp->info |= SG_INFO_CHECK;
 548	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 549		err = -EFAULT;
 550		goto err_out;
 551	}
 552err_out:
 553	err = sg_finish_rem_req(srp);
 554	return (0 == err) ? count : err;
 555}
 556
 557static ssize_t
 558sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 559{
 560	int mxsize, cmd_size, k;
 561	int input_size, blocking;
 562	unsigned char opcode;
 563	Sg_device *sdp;
 564	Sg_fd *sfp;
 565	Sg_request *srp;
 566	struct sg_header old_hdr;
 567	sg_io_hdr_t *hp;
 568	unsigned char cmnd[MAX_COMMAND_SIZE];
 569
 570	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 571		return -ENXIO;
 572	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 573				   sdp->disk->disk_name, (int) count));
 574	if (sdp->detached)
 575		return -ENODEV;
 576	if (!((filp->f_flags & O_NONBLOCK) ||
 577	      scsi_block_when_processing_errors(sdp->device)))
 578		return -ENXIO;
 579
 580	if (!access_ok(VERIFY_READ, buf, count))
 581		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
 582	if (count < SZ_SG_HEADER)
 583		return -EIO;
 584	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 585		return -EFAULT;
 586	blocking = !(filp->f_flags & O_NONBLOCK);
 587	if (old_hdr.reply_len < 0)
 588		return sg_new_write(sfp, filp, buf, count,
 589				    blocking, 0, 0, NULL);
 590	if (count < (SZ_SG_HEADER + 6))
 591		return -EIO;	/* The minimum scsi command length is 6 bytes. */
 592
 593	if (!(srp = sg_add_request(sfp))) {
 594		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 595		return -EDOM;
 596	}
 597	buf += SZ_SG_HEADER;
 598	__get_user(opcode, buf);
 599	if (sfp->next_cmd_len > 0) {
 600		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 601			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 602			sfp->next_cmd_len = 0;
 603			sg_remove_request(sfp, srp);
 604			return -EIO;
 605		}
 606		cmd_size = sfp->next_cmd_len;
 607		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
 608	} else {
 609		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
 610		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 611			cmd_size = 12;
 612	}
 613	SCSI_LOG_TIMEOUT(4, printk(
 614		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 615/* Determine buffer size.  */
 616	input_size = count - cmd_size;
 617	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 618	mxsize -= SZ_SG_HEADER;
 619	input_size -= SZ_SG_HEADER;
 620	if (input_size < 0) {
 621		sg_remove_request(sfp, srp);
 622		return -EIO;	/* User did not pass enough bytes for this command. */
 623	}
 624	hp = &srp->header;
 625	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
 626	hp->cmd_len = (unsigned char) cmd_size;
 627	hp->iovec_count = 0;
 628	hp->mx_sb_len = 0;
 629	if (input_size > 0)
 630		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 631		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 632	else
 633		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 634	hp->dxfer_len = mxsize;
 635	if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 636		hp->dxferp = (char __user *)buf + cmd_size;
 637	else
 638		hp->dxferp = NULL;
 639	hp->sbp = NULL;
 640	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
 641	hp->flags = input_size;	/* structure abuse ... */
 642	hp->pack_id = old_hdr.pack_id;
 643	hp->usr_ptr = NULL;
 644	if (__copy_from_user(cmnd, buf, cmd_size))
 645		return -EFAULT;
 646	/*
 647	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 648	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 649	 * is a non-zero input_size, so emit a warning.
 650	 */
 651	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 652		static char cmd[TASK_COMM_LEN];
 653		if (strcmp(current->comm, cmd)) {
 654			printk_ratelimited(KERN_WARNING
 655					   "sg_write: data in/out %d/%d bytes "
 656					   "for SCSI command 0x%x-- guessing "
 657					   "data in;\n   program %s not setting "
 658					   "count and/or reply_len properly\n",
 659					   old_hdr.reply_len - (int)SZ_SG_HEADER,
 660					   input_size, (unsigned int) cmnd[0],
 661					   current->comm);
 662			strcpy(cmd, current->comm);
 663		}
 664	}
 665	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 666	return (k < 0) ? k : count;
 667}
 668
 669static ssize_t
 670sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 671		 size_t count, int blocking, int read_only, int sg_io_owned,
 672		 Sg_request **o_srp)
 673{
 674	int k;
 675	Sg_request *srp;
 676	sg_io_hdr_t *hp;
 677	unsigned char cmnd[MAX_COMMAND_SIZE];
 678	int timeout;
 679	unsigned long ul_timeout;
 680
 681	if (count < SZ_SG_IO_HDR)
 682		return -EINVAL;
 683	if (!access_ok(VERIFY_READ, buf, count))
 684		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 685
 686	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
 687	if (!(srp = sg_add_request(sfp))) {
 688		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 689		return -EDOM;
 690	}
 691	srp->sg_io_owned = sg_io_owned;
 692	hp = &srp->header;
 693	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 694		sg_remove_request(sfp, srp);
 695		return -EFAULT;
 696	}
 697	if (hp->interface_id != 'S') {
 698		sg_remove_request(sfp, srp);
 699		return -ENOSYS;
 700	}
 701	if (hp->flags & SG_FLAG_MMAP_IO) {
 702		if (hp->dxfer_len > sfp->reserve.bufflen) {
 703			sg_remove_request(sfp, srp);
 704			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
 705		}
 706		if (hp->flags & SG_FLAG_DIRECT_IO) {
 707			sg_remove_request(sfp, srp);
 708			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
 709		}
 710		if (sg_res_in_use(sfp)) {
 711			sg_remove_request(sfp, srp);
 712			return -EBUSY;	/* reserve buffer already being used */
 713		}
 714	}
 715	ul_timeout = msecs_to_jiffies(srp->header.timeout);
 716	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 717	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 718		sg_remove_request(sfp, srp);
 719		return -EMSGSIZE;
 720	}
 721	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 722		sg_remove_request(sfp, srp);
 723		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
 724	}
 725	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 726		sg_remove_request(sfp, srp);
 727		return -EFAULT;
 728	}
 729	if (read_only && sg_allow_access(file, cmnd)) {
 730		sg_remove_request(sfp, srp);
 731		return -EPERM;
 732	}
 733	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 734	if (k < 0)
 735		return k;
 736	if (o_srp)
 737		*o_srp = srp;
 738	return count;
 739}
 740
 741static int
 742sg_common_write(Sg_fd * sfp, Sg_request * srp,
 743		unsigned char *cmnd, int timeout, int blocking)
 744{
 745	int k, data_dir;
 746	Sg_device *sdp = sfp->parentdp;
 747	sg_io_hdr_t *hp = &srp->header;
 748
 749	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
 750	hp->status = 0;
 751	hp->masked_status = 0;
 752	hp->msg_status = 0;
 753	hp->info = 0;
 754	hp->host_status = 0;
 755	hp->driver_status = 0;
 756	hp->resid = 0;
 757	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 758			  (int) cmnd[0], (int) hp->cmd_len));
 759
 760	k = sg_start_req(srp, cmnd);
 761	if (k) {
 762		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 763		sg_finish_rem_req(srp);
 764		return k;	/* probably out of space --> ENOMEM */
 765	}
 766	if (sdp->detached) {
 767		if (srp->bio)
 768			blk_end_request_all(srp->rq, -EIO);
 769		sg_finish_rem_req(srp);
 770		return -ENODEV;
 771	}
 772
 773	switch (hp->dxfer_direction) {
 774	case SG_DXFER_TO_FROM_DEV:
 775	case SG_DXFER_FROM_DEV:
 776		data_dir = DMA_FROM_DEVICE;
 777		break;
 778	case SG_DXFER_TO_DEV:
 779		data_dir = DMA_TO_DEVICE;
 780		break;
 781	case SG_DXFER_UNKNOWN:
 782		data_dir = DMA_BIDIRECTIONAL;
 783		break;
 784	default:
 785		data_dir = DMA_NONE;
 786		break;
 787	}
 788	hp->duration = jiffies_to_msecs(jiffies);
 789
 790	srp->rq->timeout = timeout;
 791	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 792	blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 793			      srp->rq, 1, sg_rq_end_io);
 794	return 0;
 795}
 796
 797static int srp_done(Sg_fd *sfp, Sg_request *srp)
 798{
 799	unsigned long flags;
 800	int ret;
 801
 802	read_lock_irqsave(&sfp->rq_list_lock, flags);
 803	ret = srp->done;
 804	read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 805	return ret;
 806}
 807
 808static long
 809sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 810{
 811	void __user *p = (void __user *)arg;
 812	int __user *ip = p;
 813	int result, val, read_only;
 814	Sg_device *sdp;
 815	Sg_fd *sfp;
 816	Sg_request *srp;
 817	unsigned long iflags;
 818
 819	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 820		return -ENXIO;
 821
 822	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 823				   sdp->disk->disk_name, (int) cmd_in));
 824	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 825
 826	switch (cmd_in) {
 827	case SG_IO:
 828		if (sdp->detached)
 829			return -ENODEV;
 830		if (!scsi_block_when_processing_errors(sdp->device))
 831			return -ENXIO;
 832		if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 833			return -EFAULT;
 834		result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 835				 1, read_only, 1, &srp);
 836		if (result < 0)
 837			return result;
 838		result = wait_event_interruptible(sfp->read_wait,
 839			(srp_done(sfp, srp) || sdp->detached));
 840		if (sdp->detached)
 841			return -ENODEV;
 842		write_lock_irq(&sfp->rq_list_lock);
 843		if (srp->done) {
 844			srp->done = 2;
 845			write_unlock_irq(&sfp->rq_list_lock);
 846			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 847			return (result < 0) ? result : 0;
 848		}
 849		srp->orphan = 1;
 850		write_unlock_irq(&sfp->rq_list_lock);
 851		return result;	/* -ERESTARTSYS because signal hit process */
 852	case SG_SET_TIMEOUT:
 853		result = get_user(val, ip);
 854		if (result)
 855			return result;
 856		if (val < 0)
 857			return -EIO;
 858		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 859		    val = MULDIV (INT_MAX, USER_HZ, HZ);
 860		sfp->timeout_user = val;
 861		sfp->timeout = MULDIV (val, HZ, USER_HZ);
 862
 863		return 0;
 864	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
 865				/* strange ..., for backward compatibility */
 866		return sfp->timeout_user;
 867	case SG_SET_FORCE_LOW_DMA:
 868		result = get_user(val, ip);
 869		if (result)
 870			return result;
 871		if (val) {
 872			sfp->low_dma = 1;
 873			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 874				val = (int) sfp->reserve.bufflen;
 875				sg_remove_scat(&sfp->reserve);
 876				sg_build_reserve(sfp, val);
 877			}
 878		} else {
 879			if (sdp->detached)
 880				return -ENODEV;
 881			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 882		}
 883		return 0;
 884	case SG_GET_LOW_DMA:
 885		return put_user((int) sfp->low_dma, ip);
 886	case SG_GET_SCSI_ID:
 887		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 888			return -EFAULT;
 889		else {
 890			sg_scsi_id_t __user *sg_idp = p;
 891
 892			if (sdp->detached)
 893				return -ENODEV;
 894			__put_user((int) sdp->device->host->host_no,
 895				   &sg_idp->host_no);
 896			__put_user((int) sdp->device->channel,
 897				   &sg_idp->channel);
 898			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
 899			__put_user((int) sdp->device->lun, &sg_idp->lun);
 900			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
 901			__put_user((short) sdp->device->host->cmd_per_lun,
 902				   &sg_idp->h_cmd_per_lun);
 903			__put_user((short) sdp->device->queue_depth,
 904				   &sg_idp->d_queue_depth);
 905			__put_user(0, &sg_idp->unused[0]);
 906			__put_user(0, &sg_idp->unused[1]);
 907			return 0;
 908		}
 909	case SG_SET_FORCE_PACK_ID:
 910		result = get_user(val, ip);
 911		if (result)
 912			return result;
 913		sfp->force_packid = val ? 1 : 0;
 914		return 0;
 915	case SG_GET_PACK_ID:
 916		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 917			return -EFAULT;
 918		read_lock_irqsave(&sfp->rq_list_lock, iflags);
 919		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 920			if ((1 == srp->done) && (!srp->sg_io_owned)) {
 921				read_unlock_irqrestore(&sfp->rq_list_lock,
 922						       iflags);
 923				__put_user(srp->header.pack_id, ip);
 924				return 0;
 925			}
 926		}
 927		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 928		__put_user(-1, ip);
 929		return 0;
 930	case SG_GET_NUM_WAITING:
 931		read_lock_irqsave(&sfp->rq_list_lock, iflags);
 932		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 933			if ((1 == srp->done) && (!srp->sg_io_owned))
 934				++val;
 935		}
 936		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 937		return put_user(val, ip);
 938	case SG_GET_SG_TABLESIZE:
 939		return put_user(sdp->sg_tablesize, ip);
 940	case SG_SET_RESERVED_SIZE:
 941		result = get_user(val, ip);
 942		if (result)
 943			return result;
 944                if (val < 0)
 945                        return -EINVAL;
 946		val = min_t(int, val,
 947			    queue_max_sectors(sdp->device->request_queue) * 512);
 948		if (val != sfp->reserve.bufflen) {
 949			if (sg_res_in_use(sfp) || sfp->mmap_called)
 950				return -EBUSY;
 951			sg_remove_scat(&sfp->reserve);
 952			sg_build_reserve(sfp, val);
 953		}
 954		return 0;
 955	case SG_GET_RESERVED_SIZE:
 956		val = min_t(int, sfp->reserve.bufflen,
 957			    queue_max_sectors(sdp->device->request_queue) * 512);
 958		return put_user(val, ip);
 959	case SG_SET_COMMAND_Q:
 960		result = get_user(val, ip);
 961		if (result)
 962			return result;
 963		sfp->cmd_q = val ? 1 : 0;
 964		return 0;
 965	case SG_GET_COMMAND_Q:
 966		return put_user((int) sfp->cmd_q, ip);
 967	case SG_SET_KEEP_ORPHAN:
 968		result = get_user(val, ip);
 969		if (result)
 970			return result;
 971		sfp->keep_orphan = val;
 972		return 0;
 973	case SG_GET_KEEP_ORPHAN:
 974		return put_user((int) sfp->keep_orphan, ip);
 975	case SG_NEXT_CMD_LEN:
 976		result = get_user(val, ip);
 977		if (result)
 978			return result;
 979		sfp->next_cmd_len = (val > 0) ? val : 0;
 980		return 0;
 981	case SG_GET_VERSION_NUM:
 982		return put_user(sg_version_num, ip);
 983	case SG_GET_ACCESS_COUNT:
 984		/* faked - we don't have a real access count anymore */
 985		val = (sdp->device ? 1 : 0);
 986		return put_user(val, ip);
 987	case SG_GET_REQUEST_TABLE:
 988		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 989			return -EFAULT;
 990		else {
 991			sg_req_info_t *rinfo;
 992			unsigned int ms;
 993
 994			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 995								GFP_KERNEL);
 996			if (!rinfo)
 997				return -ENOMEM;
 998			read_lock_irqsave(&sfp->rq_list_lock, iflags);
 999			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1000			     ++val, srp = srp ? srp->nextrp : srp) {
1001				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1002				if (srp) {
1003					rinfo[val].req_state = srp->done + 1;
1004					rinfo[val].problem =
1005					    srp->header.masked_status & 
1006					    srp->header.host_status & 
1007					    srp->header.driver_status;
1008					if (srp->done)
1009						rinfo[val].duration =
1010							srp->header.duration;
1011					else {
1012						ms = jiffies_to_msecs(jiffies);
1013						rinfo[val].duration =
1014						    (ms > srp->header.duration) ?
1015						    (ms - srp->header.duration) : 0;
1016					}
1017					rinfo[val].orphan = srp->orphan;
1018					rinfo[val].sg_io_owned =
1019							srp->sg_io_owned;
1020					rinfo[val].pack_id =
1021							srp->header.pack_id;
1022					rinfo[val].usr_ptr =
1023							srp->header.usr_ptr;
1024				}
1025			}
1026			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1027			result = __copy_to_user(p, rinfo, 
1028						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1029			result = result ? -EFAULT : 0;
1030			kfree(rinfo);
1031			return result;
1032		}
1033	case SG_EMULATED_HOST:
1034		if (sdp->detached)
1035			return -ENODEV;
1036		return put_user(sdp->device->host->hostt->emulated, ip);
1037	case SG_SCSI_RESET:
1038		if (sdp->detached)
1039			return -ENODEV;
1040		if (filp->f_flags & O_NONBLOCK) {
1041			if (scsi_host_in_recovery(sdp->device->host))
1042				return -EBUSY;
1043		} else if (!scsi_block_when_processing_errors(sdp->device))
1044			return -EBUSY;
1045		result = get_user(val, ip);
1046		if (result)
1047			return result;
1048		if (SG_SCSI_RESET_NOTHING == val)
1049			return 0;
1050		switch (val) {
1051		case SG_SCSI_RESET_DEVICE:
1052			val = SCSI_TRY_RESET_DEVICE;
1053			break;
1054		case SG_SCSI_RESET_TARGET:
1055			val = SCSI_TRY_RESET_TARGET;
1056			break;
1057		case SG_SCSI_RESET_BUS:
1058			val = SCSI_TRY_RESET_BUS;
1059			break;
1060		case SG_SCSI_RESET_HOST:
1061			val = SCSI_TRY_RESET_HOST;
1062			break;
1063		default:
1064			return -EINVAL;
1065		}
1066		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1067			return -EACCES;
1068		return (scsi_reset_provider(sdp->device, val) ==
1069			SUCCESS) ? 0 : -EIO;
1070	case SCSI_IOCTL_SEND_COMMAND:
1071		if (sdp->detached)
1072			return -ENODEV;
1073		if (read_only) {
1074			unsigned char opcode = WRITE_6;
1075			Scsi_Ioctl_Command __user *siocp = p;
1076
1077			if (copy_from_user(&opcode, siocp->data, 1))
1078				return -EFAULT;
1079			if (sg_allow_access(filp, &opcode))
1080				return -EPERM;
1081		}
1082		return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1083	case SG_SET_DEBUG:
1084		result = get_user(val, ip);
1085		if (result)
1086			return result;
1087		sdp->sgdebug = (char) val;
1088		return 0;
1089	case SCSI_IOCTL_GET_IDLUN:
1090	case SCSI_IOCTL_GET_BUS_NUMBER:
1091	case SCSI_IOCTL_PROBE_HOST:
1092	case SG_GET_TRANSFORM:
1093		if (sdp->detached)
1094			return -ENODEV;
1095		return scsi_ioctl(sdp->device, cmd_in, p);
1096	case BLKSECTGET:
1097		return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1098				ip);
1099	case BLKTRACESETUP:
1100		return blk_trace_setup(sdp->device->request_queue,
1101				       sdp->disk->disk_name,
1102				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1103				       NULL,
1104				       (char *)arg);
1105	case BLKTRACESTART:
1106		return blk_trace_startstop(sdp->device->request_queue, 1);
1107	case BLKTRACESTOP:
1108		return blk_trace_startstop(sdp->device->request_queue, 0);
1109	case BLKTRACETEARDOWN:
1110		return blk_trace_remove(sdp->device->request_queue);
1111	default:
1112		if (read_only)
1113			return -EPERM;	/* don't know so take safe approach */
1114		return scsi_ioctl(sdp->device, cmd_in, p);
1115	}
1116}
1117
1118#ifdef CONFIG_COMPAT
1119static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1120{
1121	Sg_device *sdp;
1122	Sg_fd *sfp;
1123	struct scsi_device *sdev;
1124
1125	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1126		return -ENXIO;
1127
1128	sdev = sdp->device;
1129	if (sdev->host->hostt->compat_ioctl) { 
1130		int ret;
1131
1132		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1133
1134		return ret;
1135	}
1136	
1137	return -ENOIOCTLCMD;
1138}
1139#endif
1140
1141static unsigned int
1142sg_poll(struct file *filp, poll_table * wait)
1143{
1144	unsigned int res = 0;
1145	Sg_device *sdp;
1146	Sg_fd *sfp;
1147	Sg_request *srp;
1148	int count = 0;
1149	unsigned long iflags;
1150
1151	sfp = filp->private_data;
1152	if (!sfp)
1153		return POLLERR;
1154	sdp = sfp->parentdp;
1155	if (!sdp)
1156		return POLLERR;
1157	poll_wait(filp, &sfp->read_wait, wait);
1158	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1159	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1160		/* if any read waiting, flag it */
1161		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1162			res = POLLIN | POLLRDNORM;
1163		++count;
1164	}
1165	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1166
1167	if (sdp->detached)
1168		res |= POLLHUP;
1169	else if (!sfp->cmd_q) {
1170		if (0 == count)
1171			res |= POLLOUT | POLLWRNORM;
1172	} else if (count < SG_MAX_QUEUE)
1173		res |= POLLOUT | POLLWRNORM;
1174	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1175				   sdp->disk->disk_name, (int) res));
1176	return res;
1177}
1178
1179static int
1180sg_fasync(int fd, struct file *filp, int mode)
1181{
1182	Sg_device *sdp;
1183	Sg_fd *sfp;
1184
1185	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1186		return -ENXIO;
1187	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1188				   sdp->disk->disk_name, mode));
1189
1190	return fasync_helper(fd, filp, mode, &sfp->async_qp);
1191}
1192
1193static int
1194sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1195{
1196	Sg_fd *sfp;
1197	unsigned long offset, len, sa;
1198	Sg_scatter_hold *rsv_schp;
1199	int k, length;
1200
1201	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1202		return VM_FAULT_SIGBUS;
1203	rsv_schp = &sfp->reserve;
1204	offset = vmf->pgoff << PAGE_SHIFT;
1205	if (offset >= rsv_schp->bufflen)
1206		return VM_FAULT_SIGBUS;
1207	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1208				   offset, rsv_schp->k_use_sg));
1209	sa = vma->vm_start;
1210	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1211	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1212		len = vma->vm_end - sa;
1213		len = (len < length) ? len : length;
1214		if (offset < len) {
1215			struct page *page = nth_page(rsv_schp->pages[k],
1216						     offset >> PAGE_SHIFT);
1217			get_page(page);	/* increment page count */
1218			vmf->page = page;
1219			return 0; /* success */
1220		}
1221		sa += len;
1222		offset -= len;
1223	}
1224
1225	return VM_FAULT_SIGBUS;
1226}
1227
1228static const struct vm_operations_struct sg_mmap_vm_ops = {
1229	.fault = sg_vma_fault,
1230};
1231
1232static int
1233sg_mmap(struct file *filp, struct vm_area_struct *vma)
1234{
1235	Sg_fd *sfp;
1236	unsigned long req_sz, len, sa;
1237	Sg_scatter_hold *rsv_schp;
1238	int k, length;
1239
1240	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1241		return -ENXIO;
1242	req_sz = vma->vm_end - vma->vm_start;
1243	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1244				   (void *) vma->vm_start, (int) req_sz));
1245	if (vma->vm_pgoff)
1246		return -EINVAL;	/* want no offset */
1247	rsv_schp = &sfp->reserve;
1248	if (req_sz > rsv_schp->bufflen)
1249		return -ENOMEM;	/* cannot map more than reserved buffer */
1250
1251	sa = vma->vm_start;
1252	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1253	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1254		len = vma->vm_end - sa;
1255		len = (len < length) ? len : length;
1256		sa += len;
1257	}
1258
1259	sfp->mmap_called = 1;
1260	vma->vm_flags |= VM_RESERVED;
1261	vma->vm_private_data = sfp;
1262	vma->vm_ops = &sg_mmap_vm_ops;
1263	return 0;
1264}
1265
1266static void sg_rq_end_io_usercontext(struct work_struct *work)
1267{
1268	struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1269	struct sg_fd *sfp = srp->parentfp;
1270
1271	sg_finish_rem_req(srp);
1272	kref_put(&sfp->f_ref, sg_remove_sfp);
1273}
1274
1275/*
1276 * This function is a "bottom half" handler that is called by the mid
1277 * level when a command is completed (or has failed).
1278 */
1279static void sg_rq_end_io(struct request *rq, int uptodate)
1280{
1281	struct sg_request *srp = rq->end_io_data;
1282	Sg_device *sdp;
1283	Sg_fd *sfp;
1284	unsigned long iflags;
1285	unsigned int ms;
1286	char *sense;
1287	int result, resid, done = 1;
1288
1289	if (WARN_ON(srp->done != 0))
1290		return;
1291
1292	sfp = srp->parentfp;
1293	if (WARN_ON(sfp == NULL))
1294		return;
1295
1296	sdp = sfp->parentdp;
1297	if (unlikely(sdp->detached))
1298		printk(KERN_INFO "sg_rq_end_io: device detached\n");
1299
1300	sense = rq->sense;
1301	result = rq->errors;
1302	resid = rq->resid_len;
1303
1304	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1305		sdp->disk->disk_name, srp->header.pack_id, result));
1306	srp->header.resid = resid;
1307	ms = jiffies_to_msecs(jiffies);
1308	srp->header.duration = (ms > srp->header.duration) ?
1309				(ms - srp->header.duration) : 0;
1310	if (0 != result) {
1311		struct scsi_sense_hdr sshdr;
1312
1313		srp->header.status = 0xff & result;
1314		srp->header.masked_status = status_byte(result);
1315		srp->header.msg_status = msg_byte(result);
1316		srp->header.host_status = host_byte(result);
1317		srp->header.driver_status = driver_byte(result);
1318		if ((sdp->sgdebug > 0) &&
1319		    ((CHECK_CONDITION == srp->header.masked_status) ||
1320		     (COMMAND_TERMINATED == srp->header.masked_status)))
1321			__scsi_print_sense("sg_cmd_done", sense,
1322					   SCSI_SENSE_BUFFERSIZE);
1323
1324		/* Following if statement is a patch supplied by Eric Youngdale */
1325		if (driver_byte(result) != 0
1326		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1327		    && !scsi_sense_is_deferred(&sshdr)
1328		    && sshdr.sense_key == UNIT_ATTENTION
1329		    && sdp->device->removable) {
1330			/* Detected possible disc change. Set the bit - this */
1331			/* may be used if there are filesystems using this device */
1332			sdp->device->changed = 1;
1333		}
1334	}
1335	/* Rely on write phase to clean out srp status values, so no "else" */
1336
1337	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1338	if (unlikely(srp->orphan)) {
1339		if (sfp->keep_orphan)
1340			srp->sg_io_owned = 0;
1341		else
1342			done = 0;
1343	}
1344	srp->done = done;
1345	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1346
1347	if (likely(done)) {
1348		/* Now wake up any sg_read() that is waiting for this
1349		 * packet.
1350		 */
1351		wake_up_interruptible(&sfp->read_wait);
1352		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1353		kref_put(&sfp->f_ref, sg_remove_sfp);
1354	} else {
1355		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1356		schedule_work(&srp->ew.work);
1357	}
1358}
1359
1360static const struct file_operations sg_fops = {
1361	.owner = THIS_MODULE,
1362	.read = sg_read,
1363	.write = sg_write,
1364	.poll = sg_poll,
1365	.unlocked_ioctl = sg_ioctl,
1366#ifdef CONFIG_COMPAT
1367	.compat_ioctl = sg_compat_ioctl,
1368#endif
1369	.open = sg_open,
1370	.mmap = sg_mmap,
1371	.release = sg_release,
1372	.fasync = sg_fasync,
1373	.llseek = no_llseek,
1374};
1375
1376static struct class *sg_sysfs_class;
1377
1378static int sg_sysfs_valid = 0;
1379
1380static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1381{
1382	struct request_queue *q = scsidp->request_queue;
1383	Sg_device *sdp;
1384	unsigned long iflags;
1385	int error;
1386	u32 k;
1387
1388	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1389	if (!sdp) {
1390		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1391		return ERR_PTR(-ENOMEM);
1392	}
1393
1394	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1395		printk(KERN_WARNING "idr expansion Sg_device failure\n");
1396		error = -ENOMEM;
1397		goto out;
1398	}
1399
1400	write_lock_irqsave(&sg_index_lock, iflags);
1401
1402	error = idr_get_new(&sg_index_idr, sdp, &k);
1403	if (error) {
1404		write_unlock_irqrestore(&sg_index_lock, iflags);
1405		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1406		       error);
1407		goto out;
1408	}
1409
1410	if (unlikely(k >= SG_MAX_DEVS))
1411		goto overflow;
1412
1413	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1414	sprintf(disk->disk_name, "sg%d", k);
1415	disk->first_minor = k;
1416	sdp->disk = disk;
1417	sdp->device = scsidp;
1418	INIT_LIST_HEAD(&sdp->sfds);
1419	init_waitqueue_head(&sdp->o_excl_wait);
1420	sdp->sg_tablesize = queue_max_segments(q);
1421	sdp->index = k;
1422	kref_init(&sdp->d_ref);
1423
1424	write_unlock_irqrestore(&sg_index_lock, iflags);
1425
1426	error = 0;
1427 out:
1428	if (error) {
1429		kfree(sdp);
1430		return ERR_PTR(error);
1431	}
1432	return sdp;
1433
1434 overflow:
1435	idr_remove(&sg_index_idr, k);
1436	write_unlock_irqrestore(&sg_index_lock, iflags);
1437	sdev_printk(KERN_WARNING, scsidp,
1438		    "Unable to attach sg device type=%d, minor "
1439		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1440	error = -ENODEV;
1441	goto out;
1442}
1443
1444static int
1445sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1446{
1447	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1448	struct gendisk *disk;
1449	Sg_device *sdp = NULL;
1450	struct cdev * cdev = NULL;
1451	int error;
1452	unsigned long iflags;
1453
1454	disk = alloc_disk(1);
1455	if (!disk) {
1456		printk(KERN_WARNING "alloc_disk failed\n");
1457		return -ENOMEM;
1458	}
1459	disk->major = SCSI_GENERIC_MAJOR;
1460
1461	error = -ENOMEM;
1462	cdev = cdev_alloc();
1463	if (!cdev) {
1464		printk(KERN_WARNING "cdev_alloc failed\n");
1465		goto out;
1466	}
1467	cdev->owner = THIS_MODULE;
1468	cdev->ops = &sg_fops;
1469
1470	sdp = sg_alloc(disk, scsidp);
1471	if (IS_ERR(sdp)) {
1472		printk(KERN_WARNING "sg_alloc failed\n");
1473		error = PTR_ERR(sdp);
1474		goto out;
1475	}
1476
1477	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1478	if (error)
1479		goto cdev_add_err;
1480
1481	sdp->cdev = cdev;
1482	if (sg_sysfs_valid) {
1483		struct device *sg_class_member;
1484
1485		sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1486						MKDEV(SCSI_GENERIC_MAJOR,
1487						      sdp->index),
1488						sdp, "%s", disk->disk_name);
1489		if (IS_ERR(sg_class_member)) {
1490			printk(KERN_ERR "sg_add: "
1491			       "device_create failed\n");
1492			error = PTR_ERR(sg_class_member);
1493			goto cdev_add_err;
1494		}
1495		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1496					  &sg_class_member->kobj, "generic");
1497		if (error)
1498			printk(KERN_ERR "sg_add: unable to make symlink "
1499					"'generic' back to sg%d\n", sdp->index);
1500	} else
1501		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1502
1503	sdev_printk(KERN_NOTICE, scsidp,
1504		    "Attached scsi generic sg%d type %d\n", sdp->index,
1505		    scsidp->type);
1506
1507	dev_set_drvdata(cl_dev, sdp);
1508
1509	return 0;
1510
1511cdev_add_err:
1512	write_lock_irqsave(&sg_index_lock, iflags);
1513	idr_remove(&sg_index_idr, sdp->index);
1514	write_unlock_irqrestore(&sg_index_lock, iflags);
1515	kfree(sdp);
1516
1517out:
1518	put_disk(disk);
1519	if (cdev)
1520		cdev_del(cdev);
1521	return error;
1522}
1523
1524static void sg_device_destroy(struct kref *kref)
1525{
1526	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1527	unsigned long flags;
1528
1529	/* CAUTION!  Note that the device can still be found via idr_find()
1530	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1531	 * any other cleanup.
1532	 */
1533
1534	write_lock_irqsave(&sg_index_lock, flags);
1535	idr_remove(&sg_index_idr, sdp->index);
1536	write_unlock_irqrestore(&sg_index_lock, flags);
1537
1538	SCSI_LOG_TIMEOUT(3,
1539		printk("sg_device_destroy: %s\n",
1540			sdp->disk->disk_name));
1541
1542	put_disk(sdp->disk);
1543	kfree(sdp);
1544}
1545
1546static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1547{
1548	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1549	Sg_device *sdp = dev_get_drvdata(cl_dev);
1550	unsigned long iflags;
1551	Sg_fd *sfp;
1552
1553	if (!sdp || sdp->detached)
1554		return;
1555
1556	SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1557
1558	/* Need a write lock to set sdp->detached. */
1559	write_lock_irqsave(&sg_index_lock, iflags);
1560	sdp->detached = 1;
1561	list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1562		wake_up_interruptible(&sfp->read_wait);
1563		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1564	}
1565	write_unlock_irqrestore(&sg_index_lock, iflags);
1566
1567	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1568	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1569	cdev_del(sdp->cdev);
1570	sdp->cdev = NULL;
1571
1572	sg_put_dev(sdp);
1573}
1574
1575module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1576module_param_named(def_reserved_size, def_reserved_size, int,
1577		   S_IRUGO | S_IWUSR);
1578module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1579
1580MODULE_AUTHOR("Douglas Gilbert");
1581MODULE_DESCRIPTION("SCSI generic (sg) driver");
1582MODULE_LICENSE("GPL");
1583MODULE_VERSION(SG_VERSION_STR);
1584MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1585
1586MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1587                "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1588MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1589MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1590
1591static int __init
1592init_sg(void)
1593{
1594	int rc;
1595
1596	if (scatter_elem_sz < PAGE_SIZE) {
1597		scatter_elem_sz = PAGE_SIZE;
1598		scatter_elem_sz_prev = scatter_elem_sz;
1599	}
1600	if (def_reserved_size >= 0)
1601		sg_big_buff = def_reserved_size;
1602	else
1603		def_reserved_size = sg_big_buff;
1604
1605	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1606				    SG_MAX_DEVS, "sg");
1607	if (rc)
1608		return rc;
1609        sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1610        if ( IS_ERR(sg_sysfs_class) ) {
1611		rc = PTR_ERR(sg_sysfs_class);
1612		goto err_out;
1613        }
1614	sg_sysfs_valid = 1;
1615	rc = scsi_register_interface(&sg_interface);
1616	if (0 == rc) {
1617#ifdef CONFIG_SCSI_PROC_FS
1618		sg_proc_init();
1619#endif				/* CONFIG_SCSI_PROC_FS */
1620		return 0;
1621	}
1622	class_destroy(sg_sysfs_class);
1623err_out:
1624	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1625	return rc;
1626}
1627
1628static void __exit
1629exit_sg(void)
1630{
1631#ifdef CONFIG_SCSI_PROC_FS
1632	sg_proc_cleanup();
1633#endif				/* CONFIG_SCSI_PROC_FS */
1634	scsi_unregister_interface(&sg_interface);
1635	class_destroy(sg_sysfs_class);
1636	sg_sysfs_valid = 0;
1637	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1638				 SG_MAX_DEVS);
1639	idr_destroy(&sg_index_idr);
1640}
1641
1642static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1643{
1644	int res;
1645	struct request *rq;
1646	Sg_fd *sfp = srp->parentfp;
1647	sg_io_hdr_t *hp = &srp->header;
1648	int dxfer_len = (int) hp->dxfer_len;
1649	int dxfer_dir = hp->dxfer_direction;
1650	unsigned int iov_count = hp->iovec_count;
1651	Sg_scatter_hold *req_schp = &srp->data;
1652	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1653	struct request_queue *q = sfp->parentdp->device->request_queue;
1654	struct rq_map_data *md, map_data;
1655	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1656
1657	SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1658				   dxfer_len));
1659
1660	rq = blk_get_request(q, rw, GFP_ATOMIC);
1661	if (!rq)
1662		return -ENOMEM;
1663
1664	memcpy(rq->cmd, cmd, hp->cmd_len);
1665
1666	rq->cmd_len = hp->cmd_len;
1667	rq->cmd_type = REQ_TYPE_BLOCK_PC;
1668
1669	srp->rq = rq;
1670	rq->end_io_data = srp;
1671	rq->sense = srp->sense_b;
1672	rq->retries = SG_DEFAULT_RETRIES;
1673
1674	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1675		return 0;
1676
1677	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1678	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1679	    !sfp->parentdp->device->host->unchecked_isa_dma &&
1680	    blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1681		md = NULL;
1682	else
1683		md = &map_data;
1684
1685	if (md) {
1686		if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1687			sg_link_reserve(sfp, srp, dxfer_len);
1688		else {
1689			res = sg_build_indirect(req_schp, sfp, dxfer_len);
1690			if (res)
1691				return res;
1692		}
1693
1694		md->pages = req_schp->pages;
1695		md->page_order = req_schp->page_order;
1696		md->nr_entries = req_schp->k_use_sg;
1697		md->offset = 0;
1698		md->null_mapped = hp->dxferp ? 0 : 1;
1699		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1700			md->from_user = 1;
1701		else
1702			md->from_user = 0;
1703	}
1704
1705	if (iov_count) {
1706		int len, size = sizeof(struct sg_iovec) * iov_count;
1707		struct iovec *iov;
1708
1709		iov = memdup_user(hp->dxferp, size);
1710		if (IS_ERR(iov))
1711			return PTR_ERR(iov);
1712
1713		len = iov_length(iov, iov_count);
1714		if (hp->dxfer_len < len) {
1715			iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1716			len = hp->dxfer_len;
1717		}
1718
1719		res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1720					  iov_count,
1721					  len, GFP_ATOMIC);
1722		kfree(iov);
1723	} else
1724		res = blk_rq_map_user(q, rq, md, hp->dxferp,
1725				      hp->dxfer_len, GFP_ATOMIC);
1726
1727	if (!res) {
1728		srp->bio = rq->bio;
1729
1730		if (!md) {
1731			req_schp->dio_in_use = 1;
1732			hp->info |= SG_INFO_DIRECT_IO;
1733		}
1734	}
1735	return res;
1736}
1737
1738static int sg_finish_rem_req(Sg_request * srp)
1739{
1740	int ret = 0;
1741
1742	Sg_fd *sfp = srp->parentfp;
1743	Sg_scatter_hold *req_schp = &srp->data;
1744
1745	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1746	if (srp->rq) {
1747		if (srp->bio)
1748			ret = blk_rq_unmap_user(srp->bio);
1749
1750		blk_put_request(srp->rq);
1751	}
1752
1753	if (srp->res_used)
1754		sg_unlink_reserve(sfp, srp);
1755	else
1756		sg_remove_scat(req_schp);
1757
1758	sg_remove_request(sfp, srp);
1759
1760	return ret;
1761}
1762
1763static int
1764sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1765{
1766	int sg_bufflen = tablesize * sizeof(struct page *);
1767	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1768
1769	schp->pages = kzalloc(sg_bufflen, gfp_flags);
1770	if (!schp->pages)
1771		return -ENOMEM;
1772	schp->sglist_len = sg_bufflen;
1773	return tablesize;	/* number of scat_gath elements allocated */
1774}
1775
1776static int
1777sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1778{
1779	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1780	int sg_tablesize = sfp->parentdp->sg_tablesize;
1781	int blk_size = buff_size, order;
1782	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1783
1784	if (blk_size < 0)
1785		return -EFAULT;
1786	if (0 == blk_size)
1787		++blk_size;	/* don't know why */
1788	/* round request up to next highest SG_SECTOR_SZ byte boundary */
1789	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1790	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1791				   buff_size, blk_size));
1792
1793	/* N.B. ret_sz carried into this block ... */
1794	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1795	if (mx_sc_elems < 0)
1796		return mx_sc_elems;	/* most likely -ENOMEM */
1797
1798	num = scatter_elem_sz;
1799	if (unlikely(num != scatter_elem_sz_prev)) {
1800		if (num < PAGE_SIZE) {
1801			scatter_elem_sz = PAGE_SIZE;
1802			scatter_elem_sz_prev = PAGE_SIZE;
1803		} else
1804			scatter_elem_sz_prev = num;
1805	}
1806
1807	if (sfp->low_dma)
1808		gfp_mask |= GFP_DMA;
1809
1810	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1811		gfp_mask |= __GFP_ZERO;
1812
1813	order = get_order(num);
1814retry:
1815	ret_sz = 1 << (PAGE_SHIFT + order);
1816
1817	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1818	     k++, rem_sz -= ret_sz) {
1819
1820		num = (rem_sz > scatter_elem_sz_prev) ?
1821			scatter_elem_sz_prev : rem_sz;
1822
1823		schp->pages[k] = alloc_pages(gfp_mask, order);
1824		if (!schp->pages[k])
1825			goto out;
1826
1827		if (num == scatter_elem_sz_prev) {
1828			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1829				scatter_elem_sz = ret_sz;
1830				scatter_elem_sz_prev = ret_sz;
1831			}
1832		}
1833
1834		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1835				 "ret_sz=%d\n", k, num, ret_sz));
1836	}		/* end of for loop */
1837
1838	schp->page_order = order;
1839	schp->k_use_sg = k;
1840	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1841			 "rem_sz=%d\n", k, rem_sz));
1842
1843	schp->bufflen = blk_size;
1844	if (rem_sz > 0)	/* must have failed */
1845		return -ENOMEM;
1846	return 0;
1847out:
1848	for (i = 0; i < k; i++)
1849		__free_pages(schp->pages[i], order);
1850
1851	if (--order >= 0)
1852		goto retry;
1853
1854	return -ENOMEM;
1855}
1856
1857static void
1858sg_remove_scat(Sg_scatter_hold * schp)
1859{
1860	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1861	if (schp->pages && schp->sglist_len > 0) {
1862		if (!schp->dio_in_use) {
1863			int k;
1864
1865			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1866				SCSI_LOG_TIMEOUT(5, printk(
1867				    "sg_remove_scat: k=%d, pg=0x%p\n",
1868				    k, schp->pages[k]));
1869				__free_pages(schp->pages[k], schp->page_order);
1870			}
1871
1872			kfree(schp->pages);
1873		}
1874	}
1875	memset(schp, 0, sizeof (*schp));
1876}
1877
1878static int
1879sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1880{
1881	Sg_scatter_hold *schp = &srp->data;
1882	int k, num;
1883
1884	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1885				   num_read_xfer));
1886	if ((!outp) || (num_read_xfer <= 0))
1887		return 0;
1888
1889	num = 1 << (PAGE_SHIFT + schp->page_order);
1890	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1891		if (num > num_read_xfer) {
1892			if (__copy_to_user(outp, page_address(schp->pages[k]),
1893					   num_read_xfer))
1894				return -EFAULT;
1895			break;
1896		} else {
1897			if (__copy_to_user(outp, page_address(schp->pages[k]),
1898					   num))
1899				return -EFAULT;
1900			num_read_xfer -= num;
1901			if (num_read_xfer <= 0)
1902				break;
1903			outp += num;
1904		}
1905	}
1906
1907	return 0;
1908}
1909
1910static void
1911sg_build_reserve(Sg_fd * sfp, int req_size)
1912{
1913	Sg_scatter_hold *schp = &sfp->reserve;
1914
1915	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1916	do {
1917		if (req_size < PAGE_SIZE)
1918			req_size = PAGE_SIZE;
1919		if (0 == sg_build_indirect(schp, sfp, req_size))
1920			return;
1921		else
1922			sg_remove_scat(schp);
1923		req_size >>= 1;	/* divide by 2 */
1924	} while (req_size > (PAGE_SIZE / 2));
1925}
1926
1927static void
1928sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1929{
1930	Sg_scatter_hold *req_schp = &srp->data;
1931	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1932	int k, num, rem;
1933
1934	srp->res_used = 1;
1935	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1936	rem = size;
1937
1938	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1939	for (k = 0; k < rsv_schp->k_use_sg; k++) {
1940		if (rem <= num) {
1941			req_schp->k_use_sg = k + 1;
1942			req_schp->sglist_len = rsv_schp->sglist_len;
1943			req_schp->pages = rsv_schp->pages;
1944
1945			req_schp->bufflen = size;
1946			req_schp->page_order = rsv_schp->page_order;
1947			break;
1948		} else
1949			rem -= num;
1950	}
1951
1952	if (k >= rsv_schp->k_use_sg)
1953		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1954}
1955
1956static void
1957sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1958{
1959	Sg_scatter_hold *req_schp = &srp->data;
1960
1961	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1962				   (int) req_schp->k_use_sg));
1963	req_schp->k_use_sg = 0;
1964	req_schp->bufflen = 0;
1965	req_schp->pages = NULL;
1966	req_schp->page_order = 0;
1967	req_schp->sglist_len = 0;
1968	sfp->save_scat_len = 0;
1969	srp->res_used = 0;
1970}
1971
1972static Sg_request *
1973sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1974{
1975	Sg_request *resp;
1976	unsigned long iflags;
1977
1978	write_lock_irqsave(&sfp->rq_list_lock, iflags);
1979	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1980		/* look for requests that are ready + not SG_IO owned */
1981		if ((1 == resp->done) && (!resp->sg_io_owned) &&
1982		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1983			resp->done = 2;	/* guard against other readers */
1984			break;
1985		}
1986	}
1987	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1988	return resp;
1989}
1990
1991/* always adds to end of list */
1992static Sg_request *
1993sg_add_request(Sg_fd * sfp)
1994{
1995	int k;
1996	unsigned long iflags;
1997	Sg_request *resp;
1998	Sg_request *rp = sfp->req_arr;
1999
2000	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2001	resp = sfp->headrp;
2002	if (!resp) {
2003		memset(rp, 0, sizeof (Sg_request));
2004		rp->parentfp = sfp;
2005		resp = rp;
2006		sfp->headrp = resp;
2007	} else {
2008		if (0 == sfp->cmd_q)
2009			resp = NULL;	/* command queuing disallowed */
2010		else {
2011			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2012				if (!rp->parentfp)
2013					break;
2014			}
2015			if (k < SG_MAX_QUEUE) {
2016				memset(rp, 0, sizeof (Sg_request));
2017				rp->parentfp = sfp;
2018				while (resp->nextrp)
2019					resp = resp->nextrp;
2020				resp->nextrp = rp;
2021				resp = rp;
2022			} else
2023				resp = NULL;
2024		}
2025	}
2026	if (resp) {
2027		resp->nextrp = NULL;
2028		resp->header.duration = jiffies_to_msecs(jiffies);
2029	}
2030	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2031	return resp;
2032}
2033
2034/* Return of 1 for found; 0 for not found */
2035static int
2036sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2037{
2038	Sg_request *prev_rp;
2039	Sg_request *rp;
2040	unsigned long iflags;
2041	int res = 0;
2042
2043	if ((!sfp) || (!srp) || (!sfp->headrp))
2044		return res;
2045	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2046	prev_rp = sfp->headrp;
2047	if (srp == prev_rp) {
2048		sfp->headrp = prev_rp->nextrp;
2049		prev_rp->parentfp = NULL;
2050		res = 1;
2051	} else {
2052		while ((rp = prev_rp->nextrp)) {
2053			if (srp == rp) {
2054				prev_rp->nextrp = rp->nextrp;
2055				rp->parentfp = NULL;
2056				res = 1;
2057				break;
2058			}
2059			prev_rp = rp;
2060		}
2061	}
2062	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2063	return res;
2064}
2065
2066static Sg_fd *
2067sg_add_sfp(Sg_device * sdp, int dev)
2068{
2069	Sg_fd *sfp;
2070	unsigned long iflags;
2071	int bufflen;
2072
2073	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2074	if (!sfp)
2075		return NULL;
2076
2077	init_waitqueue_head(&sfp->read_wait);
2078	rwlock_init(&sfp->rq_list_lock);
2079
2080	kref_init(&sfp->f_ref);
2081	sfp->timeout = SG_DEFAULT_TIMEOUT;
2082	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2083	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2084	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2085	    sdp->device->host->unchecked_isa_dma : 1;
2086	sfp->cmd_q = SG_DEF_COMMAND_Q;
2087	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2088	sfp->parentdp = sdp;
2089	write_lock_irqsave(&sg_index_lock, iflags);
2090	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2091	write_unlock_irqrestore(&sg_index_lock, iflags);
2092	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2093	if (unlikely(sg_big_buff != def_reserved_size))
2094		sg_big_buff = def_reserved_size;
2095
2096	bufflen = min_t(int, sg_big_buff,
2097			queue_max_sectors(sdp->device->request_queue) * 512);
2098	sg_build_reserve(sfp, bufflen);
2099	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2100			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2101
2102	kref_get(&sdp->d_ref);
2103	__module_get(THIS_MODULE);
2104	return sfp;
2105}
2106
2107static void sg_remove_sfp_usercontext(struct work_struct *work)
2108{
2109	struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2110	struct sg_device *sdp = sfp->parentdp;
2111
2112	/* Cleanup any responses which were never read(). */
2113	while (sfp->headrp)
2114		sg_finish_rem_req(sfp->headrp);
2115
2116	if (sfp->reserve.bufflen > 0) {
2117		SCSI_LOG_TIMEOUT(6,
2118			printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2119				(int) sfp->reserve.bufflen,
2120				(int) sfp->reserve.k_use_sg));
2121		sg_remove_scat(&sfp->reserve);
2122	}
2123
2124	SCSI_LOG_TIMEOUT(6,
2125		printk("sg_remove_sfp: %s, sfp=0x%p\n",
2126			sdp->disk->disk_name,
2127			sfp));
2128	kfree(sfp);
2129
2130	scsi_device_put(sdp->device);
2131	sg_put_dev(sdp);
2132	module_put(THIS_MODULE);
2133}
2134
2135static void sg_remove_sfp(struct kref *kref)
2136{
2137	struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2138	struct sg_device *sdp = sfp->parentdp;
2139	unsigned long iflags;
2140
2141	write_lock_irqsave(&sg_index_lock, iflags);
2142	list_del(&sfp->sfd_siblings);
2143	write_unlock_irqrestore(&sg_index_lock, iflags);
2144	wake_up_interruptible(&sdp->o_excl_wait);
2145
2146	INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2147	schedule_work(&sfp->ew.work);
2148}
2149
2150static int
2151sg_res_in_use(Sg_fd * sfp)
2152{
2153	const Sg_request *srp;
2154	unsigned long iflags;
2155
2156	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2157	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2158		if (srp->res_used)
2159			break;
2160	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2161	return srp ? 1 : 0;
2162}
2163
2164#ifdef CONFIG_SCSI_PROC_FS
2165static int
2166sg_idr_max_id(int id, void *p, void *data)
2167{
2168	int *k = data;
2169
2170	if (*k < id)
2171		*k = id;
2172
2173	return 0;
2174}
2175
2176static int
2177sg_last_dev(void)
2178{
2179	int k = -1;
2180	unsigned long iflags;
2181
2182	read_lock_irqsave(&sg_index_lock, iflags);
2183	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2184	read_unlock_irqrestore(&sg_index_lock, iflags);
2185	return k + 1;		/* origin 1 */
2186}
2187#endif
2188
2189/* must be called with sg_index_lock held */
2190static Sg_device *sg_lookup_dev(int dev)
2191{
2192	return idr_find(&sg_index_idr, dev);
2193}
2194
2195static Sg_device *sg_get_dev(int dev)
2196{
2197	struct sg_device *sdp;
2198	unsigned long flags;
2199
2200	read_lock_irqsave(&sg_index_lock, flags);
2201	sdp = sg_lookup_dev(dev);
2202	if (!sdp)
2203		sdp = ERR_PTR(-ENXIO);
2204	else if (sdp->detached) {
2205		/* If sdp->detached, then the refcount may already be 0, in
2206		 * which case it would be a bug to do kref_get().
2207		 */
2208		sdp = ERR_PTR(-ENODEV);
2209	} else
2210		kref_get(&sdp->d_ref);
2211	read_unlock_irqrestore(&sg_index_lock, flags);
2212
2213	return sdp;
2214}
2215
2216static void sg_put_dev(struct sg_device *sdp)
2217{
2218	kref_put(&sdp->d_ref, sg_device_destroy);
2219}
2220
2221#ifdef CONFIG_SCSI_PROC_FS
2222
2223static struct proc_dir_entry *sg_proc_sgp = NULL;
2224
2225static char sg_proc_sg_dirname[] = "scsi/sg";
2226
2227static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2228
2229static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2230static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2231			          size_t count, loff_t *off);
2232static const struct file_operations adio_fops = {
2233	.owner = THIS_MODULE,
2234	.open = sg_proc_single_open_adio,
2235	.read = seq_read,
2236	.llseek = seq_lseek,
2237	.write = sg_proc_write_adio,
2238	.release = single_release,
2239};
2240
2241static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2242static ssize_t sg_proc_write_dressz(struct file *filp, 
2243		const char __user *buffer, size_t count, loff_t *off);
2244static const struct file_operations dressz_fops = {
2245	.owner = THIS_MODULE,
2246	.open = sg_proc_single_open_dressz,
2247	.read = seq_read,
2248	.llseek = seq_lseek,
2249	.write = sg_proc_write_dressz,
2250	.release = single_release,
2251};
2252
2253static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2254static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2255static const struct file_operations version_fops = {
2256	.owner = THIS_MODULE,
2257	.open = sg_proc_single_open_version,
2258	.read = seq_read,
2259	.llseek = seq_lseek,
2260	.release = single_release,
2261};
2262
2263static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2264static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2265static const struct file_operations devhdr_fops = {
2266	.owner = THIS_MODULE,
2267	.open = sg_proc_single_open_devhdr,
2268	.read = seq_read,
2269	.llseek = seq_lseek,
2270	.release = single_release,
2271};
2272
2273static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2274static int sg_proc_open_dev(struct inode *inode, struct file *file);
2275static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2276static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2277static void dev_seq_stop(struct seq_file *s, void *v);
2278static const struct file_operations dev_fops = {
2279	.owner = THIS_MODULE,
2280	.open = sg_proc_open_dev,
2281	.read = seq_read,
2282	.llseek = seq_lseek,
2283	.release = seq_release,
2284};
2285static const struct seq_operations dev_seq_ops = {
2286	.start = dev_seq_start,
2287	.next  = dev_seq_next,
2288	.stop  = dev_seq_stop,
2289	.show  = sg_proc_seq_show_dev,
2290};
2291
2292static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2293static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2294static const struct file_operations devstrs_fops = {
2295	.owner = THIS_MODULE,
2296	.open = sg_proc_open_devstrs,
2297	.read = seq_read,
2298	.llseek = seq_lseek,
2299	.release = seq_release,
2300};
2301static const struct seq_operations devstrs_seq_ops = {
2302	.start = dev_seq_start,
2303	.next  = dev_seq_next,
2304	.stop  = dev_seq_stop,
2305	.show  = sg_proc_seq_show_devstrs,
2306};
2307
2308static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2309static int sg_proc_open_debug(struct inode *inode, struct file *file);
2310static const struct file_operations debug_fops = {
2311	.owner = THIS_MODULE,
2312	.open = sg_proc_open_debug,
2313	.read = seq_read,
2314	.llseek = seq_lseek,
2315	.release = seq_release,
2316};
2317static const struct seq_operations debug_seq_ops = {
2318	.start = dev_seq_start,
2319	.next  = dev_seq_next,
2320	.stop  = dev_seq_stop,
2321	.show  = sg_proc_seq_show_debug,
2322};
2323
2324
2325struct sg_proc_leaf {
2326	const char * name;
2327	const struct file_operations * fops;
2328};
2329
2330static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2331	{"allow_dio", &adio_fops},
2332	{"debug", &debug_fops},
2333	{"def_reserved_size", &dressz_fops},
2334	{"device_hdr", &devhdr_fops},
2335	{"devices", &dev_fops},
2336	{"device_strs", &devstrs_fops},
2337	{"version", &version_fops}
2338};
2339
2340static int
2341sg_proc_init(void)
2342{
2343	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2344	int k;
2345
2346	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2347	if (!sg_proc_sgp)
2348		return 1;
2349	for (k = 0; k < num_leaves; ++k) {
2350		const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2351		umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2352		proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2353	}
2354	return 0;
2355}
2356
2357static void
2358sg_proc_cleanup(void)
2359{
2360	int k;
2361	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2362
2363	if (!sg_proc_sgp)
2364		return;
2365	for (k = 0; k < num_leaves; ++k)
2366		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2367	remove_proc_entry(sg_proc_sg_dirname, NULL);
2368}
2369
2370
2371static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2372{
2373	seq_printf(s, "%d\n", *((int *)s->private));
2374	return 0;
2375}
2376
2377static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2378{
2379	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2380}
2381
2382static ssize_t 
2383sg_proc_write_adio(struct file *filp, const char __user *buffer,
2384		   size_t count, loff_t *off)
2385{
2386	int err;
2387	unsigned long num;
2388
2389	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2390		return -EACCES;
2391	err = kstrtoul_from_user(buffer, count, 0, &num);
2392	if (err)
2393		return err;
2394	sg_allow_dio = num ? 1 : 0;
2395	return count;
2396}
2397
2398static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2399{
2400	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2401}
2402
2403static ssize_t 
2404sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2405		     size_t count, loff_t *off)
2406{
2407	int err;
2408	unsigned long k = ULONG_MAX;
2409
2410	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2411		return -EACCES;
2412
2413	err = kstrtoul_from_user(buffer, count, 0, &k);
2414	if (err)
2415		return err;
2416	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2417		sg_big_buff = k;
2418		return count;
2419	}
2420	return -ERANGE;
2421}
2422
2423static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2424{
2425	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2426		   sg_version_date);
2427	return 0;
2428}
2429
2430static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2431{
2432	return single_open(file, sg_proc_seq_show_version, NULL);
2433}
2434
2435static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2436{
2437	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2438		   "online\n");
2439	return 0;
2440}
2441
2442static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2443{
2444	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2445}
2446
2447struct sg_proc_deviter {
2448	loff_t	index;
2449	size_t	max;
2450};
2451
2452static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2453{
2454	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2455
2456	s->private = it;
2457	if (! it)
2458		return NULL;
2459
2460	it->index = *pos;
2461	it->max = sg_last_dev();
2462	if (it->index >= it->max)
2463		return NULL;
2464	return it;
2465}
2466
2467static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2468{
2469	struct sg_proc_deviter * it = s->private;
2470
2471	*pos = ++it->index;
2472	return (it->index < it->max) ? it : NULL;
2473}
2474
2475static void dev_seq_stop(struct seq_file *s, void *v)
2476{
2477	kfree(s->private);
2478}
2479
2480static int sg_proc_open_dev(struct inode *inode, struct file *file)
2481{
2482        return seq_open(file, &dev_seq_ops);
2483}
2484
2485static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2486{
2487	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2488	Sg_device *sdp;
2489	struct scsi_device *scsidp;
2490	unsigned long iflags;
2491
2492	read_lock_irqsave(&sg_index_lock, iflags);
2493	sdp = it ? sg_lookup_dev(it->index) : NULL;
2494	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2495		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2496			      scsidp->host->host_no, scsidp->channel,
2497			      scsidp->id, scsidp->lun, (int) scsidp->type,
2498			      1,
2499			      (int) scsidp->queue_depth,
2500			      (int) scsidp->device_busy,
2501			      (int) scsi_device_online(scsidp));
2502	else
2503		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2504	read_unlock_irqrestore(&sg_index_lock, iflags);
2505	return 0;
2506}
2507
2508static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2509{
2510        return seq_open(file, &devstrs_seq_ops);
2511}
2512
2513static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2514{
2515	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2516	Sg_device *sdp;
2517	struct scsi_device *scsidp;
2518	unsigned long iflags;
2519
2520	read_lock_irqsave(&sg_index_lock, iflags);
2521	sdp = it ? sg_lookup_dev(it->index) : NULL;
2522	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2523		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2524			   scsidp->vendor, scsidp->model, scsidp->rev);
2525	else
2526		seq_printf(s, "<no active device>\n");
2527	read_unlock_irqrestore(&sg_index_lock, iflags);
2528	return 0;
2529}
2530
2531/* must be called while holding sg_index_lock */
2532static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2533{
2534	int k, m, new_interface, blen, usg;
2535	Sg_request *srp;
2536	Sg_fd *fp;
2537	const sg_io_hdr_t *hp;
2538	const char * cp;
2539	unsigned int ms;
2540
2541	k = 0;
2542	list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2543		k++;
2544		read_lock(&fp->rq_list_lock); /* irqs already disabled */
2545		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2546			   "(res)sgat=%d low_dma=%d\n", k,
2547			   jiffies_to_msecs(fp->timeout),
2548			   fp->reserve.bufflen,
2549			   (int) fp->reserve.k_use_sg,
2550			   (int) fp->low_dma);
2551		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2552			   (int) fp->cmd_q, (int) fp->force_packid,
2553			   (int) fp->keep_orphan);
2554		for (m = 0, srp = fp->headrp;
2555				srp != NULL;
2556				++m, srp = srp->nextrp) {
2557			hp = &srp->header;
2558			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2559			if (srp->res_used) {
2560				if (new_interface && 
2561				    (SG_FLAG_MMAP_IO & hp->flags))
2562					cp = "     mmap>> ";
2563				else
2564					cp = "     rb>> ";
2565			} else {
2566				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2567					cp = "     dio>> ";
2568				else
2569					cp = "     ";
2570			}
2571			seq_printf(s, cp);
2572			blen = srp->data.bufflen;
2573			usg = srp->data.k_use_sg;
2574			seq_printf(s, srp->done ? 
2575				   ((1 == srp->done) ?  "rcv:" : "fin:")
2576				   : "act:");
2577			seq_printf(s, " id=%d blen=%d",
2578				   srp->header.pack_id, blen);
2579			if (srp->done)
2580				seq_printf(s, " dur=%d", hp->duration);
2581			else {
2582				ms = jiffies_to_msecs(jiffies);
2583				seq_printf(s, " t_o/elap=%d/%d",
2584					(new_interface ? hp->timeout :
2585						  jiffies_to_msecs(fp->timeout)),
2586					(ms > hp->duration ? ms - hp->duration : 0));
2587			}
2588			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2589				   (int) srp->data.cmd_opcode);
2590		}
2591		if (0 == m)
2592			seq_printf(s, "     No requests active\n");
2593		read_unlock(&fp->rq_list_lock);
2594	}
2595}
2596
2597static int sg_proc_open_debug(struct inode *inode, struct file *file)
2598{
2599        return seq_open(file, &debug_seq_ops);
2600}
2601
2602static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2603{
2604	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2605	Sg_device *sdp;
2606	unsigned long iflags;
2607
2608	if (it && (0 == it->index)) {
2609		seq_printf(s, "max_active_device=%d(origin 1)\n",
2610			   (int)it->max);
2611		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2612	}
2613
2614	read_lock_irqsave(&sg_index_lock, iflags);
2615	sdp = it ? sg_lookup_dev(it->index) : NULL;
2616	if (sdp && !list_empty(&sdp->sfds)) {
2617		struct scsi_device *scsidp = sdp->device;
2618
2619		seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2620		if (sdp->detached)
2621			seq_printf(s, "detached pending close ");
2622		else
2623			seq_printf
2624			    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2625			     scsidp->host->host_no,
2626			     scsidp->channel, scsidp->id,
2627			     scsidp->lun,
2628			     scsidp->host->hostt->emulated);
2629		seq_printf(s, " sg_tablesize=%d excl=%d\n",
2630			   sdp->sg_tablesize, get_exclude(sdp));
2631		sg_proc_debug_helper(s, sdp);
2632	}
2633	read_unlock_irqrestore(&sg_index_lock, iflags);
2634	return 0;
2635}
2636
2637#endif				/* CONFIG_SCSI_PROC_FS */
2638
2639module_init(init_sg);
2640module_exit(exit_sg);